One menu, every language
Dual Audio was one of the dark buttons on the old DudeFilms, and today it lives inside every streaming app. Start the film, tap the speech-bubble icon for Audio and Subtitles, and pick the language. The big South releases usually carry Hindi, Tamil, Telugu, Kannada and Malayalam together, and most Hollywood blockbusters carry Hindi in India.
South films in Hindi
RRR, Bāhubali 2: The Conclusion, K.G.F: Chapter 1, K.G.F: Chapter 2, Kantara, Kalki 2898-AD, Pushpa 2 - The Rule and Salaar: Part 1 - Ceasefire all opened across India in several languages at once. Their Hindi versions are some of the most watched films of the decade.
Hollywood in Hindi
Avengers: Endgame, Spider-Man: No Way Home, Deadpool & Wolverine and the other big franchise films usually arrive with Hindi tracks. Each service chooses its own tracks, so check the audio list in the first minute.
The original sound
Some films are best in the language they were made in. Hellaro in Gujarati, Manjummel Boys in Malayalam and Jai Bhim in Tamil keep every performance exactly as it was, and subtitles make them easy to follow. The subtitles guide covers that side.