The audio menu does it all
Dual Audio was one of the busiest buttons on the old DownloadHub, and today every streaming app has it built in. Start the movie, tap the speech bubble or the Audio and Subtitles icon, and choose the language. Many Hollywood releases carry a Hindi track in India, and the big South Indian films usually carry Hindi, Tamil, Telugu, Kannada and Malayalam together.
South Indian films in Hindi
The pan-India releases were made for this. Bāhubali: The Beginning, Bāhubali 2: The Conclusion, K.G.F: Chapter 1, K.G.F: Chapter 2, Pushpa: The Rise, Kantara and Kalki 2898-AD all opened across India in several languages at once, and the Hindi versions are some of the most watched. The South Indian guide has the full list.
Hollywood in Hindi
Superhero films, the Harry Potter series and the big action franchises usually arrive in India with Hindi audio. Avengers: Endgame, Spider-Man: No Way Home and Mission: Impossible - Fallout are favourites to watch in Hindi with the family. Each service decides its own tracks, so the audio list can differ from one app to the next.
Checking before you start
On JustWatch, open the service's page and look at the audio languages listed there, or start the film and check the menu in the first minute. The Language line in each DownloadHub post shows the original language the film was made in. The subtitles guide covers captions.