‘The three big ‘no’s in Indian cinema are sexuality, religion and politics,” says Anurag Kashyap. “And in Sacred Games we address all three.” The Netflix series, which Kashyap co-directed, takes viewers to places Bollywood rarely does. It could be seen as India’s answer to Narcos: a dense, tense crime saga that closely tracks real-world history: political and police corruption, organised crime, religious tension, nuclear terrorism. The story switches between the present day, where a Sikh detective (Saif Ali Khan) gets wind of an imminent terrorist attack on Mumbai, and the 1980s, tracking the rise of a charismatic but ruthless gangster (played by Nawazuddin Siddiqui). There is blood, sex, and violence, not to mention a trailblazing transgender character. “You cannot do that in mainstream cinema and have an audience,” Kashyap says. “It’s a given that movie-watching in India is a family experience, a community experience. Families didn’t sit together to see Sacred Games.”

Kashyap is a maverick in Indian cinema. For 15 years, he has operated outside the commercial mainstream, writing, directing and producing provocative, relatively low-budget movies at a prodigious rate. But now Kashyap finds himself at the crest of a new wave of Indian content that could permanently alter the landscape. With 1.3 billion people and more than 500 million internet subscribers, not to mention flatlining growth in other territories, the streaming giants have been moving into India big time. Both Netflix and Amazon launched their services there in 2016, taking on larger local rivals such as the Disney-owned Hotstar. Amazon pledged to create 17 original Indian series; Netflix 16 original series and 22 films. Not only are these companies telling stories Bollywood can’t, they are bringing them to audiences Bollywood can’t reach. Sacred Games was a phenomenon in India, but the show was watched by twice as many people outside the country, according to Netflix.

“What we managed with Sacred Games is to create a sense of time and place,” Kashyap told me at June’s London Indian film festival. “Hindi cinema doesn’t give you that context; they’re stories set in la la land: it could be India, it could be Mexico, it could be anywhere. But through Sacred Games you also understand the country, and that, for me, is the hallmark of a great show.”

Kashyap’s relationship with Netflix began when they acquired his celebrated 2013 movie Gangs of Wasseypur – a five-hour smalltown gangster epic in two parts. Netflix producer Erik Barmack reached out to Kashyap and his production partner Vikramaditya Motwane (who co-directs Sacred Games), and things moved along quickly. “They gave me a lot of freedom to work the way I wanted, to change the script, improvising, changing the cast. Normally that doesn’t happen,” he says. “Netflix is like home. I can sit round a table and argue and discuss and fight about the content I’m trying to do, but after all the conflict, they actually listen to you.” He is already developing other projects with the company.

Sacred Games is not the only boundary-pushing Indian show Netflix has released. There is supernatural horror Ghoul, set in a detention facility in a near-future India under martial law due to sectarian violence. There is cricketing drama Selection Day, based on the book by Booker prize-winner Aravind Adiga, and directed by British-Indian Udayan Prasad. On a very different tack was Lust Stories, an anthology of short films by four directors (including Kashyap), all focusing on female sexuality. In one of them, a married school teacher (Radhika Apte, who also stars in Sacred Games and Ghoul) has an affair with a pupil. In another, an unsatisfied bride-to-be borrows her friend’s bullet vibrator – cue comedy mix-ups with the TV remote. Amazon has also put out provocative content, such as Mirzapur, a crime saga infused with sex and violence, that would not get past the cinema censors.

At the other end of the spectrum was this year’s Delhi Crime, based on the horrific gang rape, torture and murder of Jyoti Singh on a Delhi bus in 2012. The incident provoked an international outrage and mass protests across India, but Delhi Crime focuses on the manhunt for the six perpetrators, based on the real-life case files. The investigation is spearheaded by a female deputy police commissioner. Having seen the victim’s condition in hospital on the first night, she personally takes charge of the case, and barely sleeps or goes home until she has caught the men – which took just six days. Powerfully portrayed by Shefali Shah, she is a different kind of heroine to the Bollywood norm: fortysomething, a sympathetic mother but also a formidable leader, who insists everything is done by the book. “I believe the case was solved because this woman reacted as a human being and said, ‘OK, this is one of those not-on-my-watch moments,’” says writer and director Richie Mehta.

If Sacred Games is India’s answer to Narcos, Delhi Crime is closer to The Wire: a pacy police procedural that doubles as a wide-ranging societal survey. Although it is sympathetic towards the police, the series hardly casts India in a flattering light. This is a landscape of institutional sexism, societal indifference, self-serving politicians, endemic corruption, press leaks, power cuts, pollution and badly funded public services. Even to get a forensic team to a crime scene requires twisting arms and calling in favours.

Like Kashyap, Mehta is something of an outsider: he is primarily based in Canada. He was preparing Delhi Crime as a feature until he met former HBO co-head of drama David Levine, who suggested he turn it into a series. This was three years before Netflix or Amazon came to India, so it was a risky movie. Levine referred him to The Wire to learn the ropes, he says, but he was equally influenced by movies such as The French Connection.

Mehta’s earlier, India-set films, Amal and Siddharth, played at festivals and garnered critical praise, but the reaction to Delhi Crime was of a different order, he says. “I’ve never had anything that, once it was released, was essentially within a few days seen by everyone I’d ever known around the world, in every language.” A second season of Delhi Crime is now in the works, with the same cast working on a different case. Mehta is executive producing it, as well as developing new long-form ideas of his own. “Before I used to say, if it’s going to be a series, it really really needs to be justified, which is still true. But now it’s more the other way round, where I’m like, if it’s a film it’s really got to be justified. My ambition has now increased. I’m starting to conceive of stories that are 10, 15, 20 hours long.”

Even in cinemas, streaming giants are exerting an influence on Indian cinema, it seems. Out in the UK this month is Photograph, the latest movie from director Ritesh Batra, who scored a global hit with The Lunchbox, a decorous, gastronomic romance set in Mumbai. Photograph operates in a similar vein, bringing together a lowly Mumbai portrait photographer (Siddiqui again) and one of his subjects (wealthier student Sanya Malhotra) whom he convinces to pose as his fiancee to get his grandmother off his back. Like The Lunchbox (whose co-producer, incidentally, was Kashyap), and unlike the harder-hitting Netflix fare, Photograph is a gentle, almost old-fashioned tale of courtship, albeit in a down-to-earth Mumbai setting. It is being released in the UK by Curzon but in the US, India and Japan it is distributed by Amazon Studios, who became involved in the project at an early stage.

Between The Lunchbox and Photograph, Batra made two films in English: British drama The Sense of an Ending, adapted from the Julian Barnes novel. Then Our Souls at Night, another tender romance, starring Robert Redford and Jane Fonda. Redford called him up and asked him to direct it, having seen The Lunchbox. Batra, who is based in New York, seems unfazed by the experience: “Robert is super-collaborative, so is Jane. They were up for anything. We would do 18 takes sometimes.”

Our Souls at Night was a Netflix production. It almost goes without saying that Batra is now preparing his own long-form web series. All he will reveal is that it is “based on a great Indian novel”. He cannot say more, although last year Netflix also announced it is making its own version of Salman Rushdie’s Midnight’s Children.

“I’m very appreciative of the streamers and their influence on cinema culture,” Batra says. Indian cinema is something of a closed shop. Even getting The Lunchbox released there was a challenge (although it eventually played in cinemas for nine months). “It’s very hard to get access to cinemas for different kinds of movies. Once something is working you cannot convince people to give the audience variety or choice, you can just keep doing more of the same, but what the streamers will hopefully do is broaden audiences’ palette, so they start demanding different fare in cinemas too. That should be good for the kind of movies that I and other film-makers want to make in India.”

All the same, bigger Bollywood players are now getting in on the digital game. Legendary actor Shah Rukh Khan, for example, is producing two new shows for Netflix, a spy thriller and a zombie drama. Screen goddess Madhuri Dixit also produced her own Netflix film, 15 August. Meanwhile, Kabir Khan, who has directed some of the country’s biggest hits, is finishing off an epic series for Amazon on nationalist Subhas Chandra Bose, leader of the wartime Indian National Army. And Oscar-winning British film-maker Asif Kapadia is executive-producing The Last Hour, a supernatural thriller series, for Amazon. Netflix also has plenty more to come, including an adaptation of bestseller Cobalt Blue, about a brother and sister who fall for the same man. There are also second series of Delhi Crime, Selection Day and, most anticipated of all, Sacred Games, in mid-August. The first season, which only covered about a third of Vikram Chandra’s source novel, ended on a cliffhanger. The second is set to be even higher profile, inside and outside India.

Could this be the beginning of a brain-drain in Indian cinema? Could the streaming services start to erode Bollywood? Just as House of Cards marked the start of an exodus from Hollywood to digital platforms, so shows such as Sacred Games could augur the same for India. There is something to lose here. For all its inaccessibility, Bollywood is really the only substantial national cinema that has not been co-opted by the US and other foreign players. As Kashyap puts it: “Our biggest strength is our biggest weakness: that we do not need to sell a single ticket to a non-Indian to sustain ourselves.” It doesn’t have to be a zero-sum game, but the streaming companies have created an extra platform for more outward-facing Indian film-makers such as Kashyap, Mehta and Batra. Having been outsiders, they now find themselves in a position of unprecedented power and influence. The game has changed.

• Photograph is released on 2 August and series two of Sacred Games on 15 August.