Show a pop-up or pop-up like asking if they want to switch to an Indian language.
I never switch to another language other than English.
It is highly advisable that companies translate to eight most common Indian languages. Or even the top five [0].
People speaking all major languages of India are huge potential markets for companies. Google offers search in nine Indian languages. Amazon provides customer services in five languages.
For some services, you should not even want to translate to languages other than English. India has one of the largest English speaking populace of the world- 2nd only after the US [1].
Especially where people willfully get arrested to wipe down Hindi marks from metro stations [0] and people who have fasted to death to not have Hindi as the national language [1].