Currently you can stream India's Daughter through both Prime Video and Kanopy. If you're based in the United States and you have an existing Prime Video subscription then it'll cost you nothing extra to stream India's Daughter. You can access the Kanopy streaming service through your university or library.
If you don't have access to Prime Video or Kanopy to stream the documentary, then you can buy or rent India's Daughter via Vimeo. It will cost you $3.99 to rent India's Daughter through Vimeo. It's great to rent movies through Vimeo because a fairer portion of the revenue goes to the filmmakers.