This is based on the following:
* He is from Mumbai, India: Mumbai is a predominantly Hindi-speaking city.
* He works in Bollywood: Bollywood films primarily use Hindi dialogue.
* He speaks fluent Hindi: This is evident in interviews and television appearances.
However, it's important to note that there are many different languages spoken in India. It's possible that he speaks another language fluently, but Hindi is the most likely to be his mother tongue.