There are many languages used in India.
My mother tongue is Marathi. Hindi is national language. English is primarily used in academics, businesses, etc. Southern states practice English to more extent compared with other states.
Sanskrit, like Latin, has been origin to many languages here; though it is not dead. It is still used. Ancient books are in Sanskrit. And, I learned it as a third language in school and college.
And, it’s still not easy to count how many languages there are in India only. Thus, it will be extremely difficult to count them in the world.
As far as I know, there are six varieties of Chinese languages in addition to Mandarin.
And, there are dialects too. There are many dialects in Marathi only. Thinking about the world, it just spins my head right around!