The documentary goes behind the scenes of a Bollywood film, Shootout at Lokhandwala, starring Bollywood screen legend Sanjay Dutt.
US director Mermin, who previously directed Office Tigers and The Beauty Academy of Kabul, shot the project over six months in Mumbai.
The film includes the last interview with Dutt before his prison sentence earlier this year over illegal arms possession.
Nahrein Mirza produced for UK-based production company Little Bird.
In Apoorva Lakhia's film examined in the documentary, Dutt plays AA Khan, a Mumbai police officer involved in a shootout with local gangsters. Shot In Bombay also talks to the real Mumbai police involved in the 1991 incident on which that film is based.
The documentary also features Amitabh Bachchan, Abhishek Bachchan, Vivek Oberoi, Sunil Shetty, Arbaaz Khan, Tusshar Kapoor, and Diya Mirza.
The feature-length documentary is also backed by BBC Storyville and the Sundance Channel.