Proposal: Indian Languages
There are 22 major Indian languages and still hundreds more out there. They are all probably different from each other so maintaining relevance on the site would be very hard for moderators, which we are lucky to have.
Main users of this site would be Indians, who can help out teaching others. This brings up the problem of communication. If users don't share a common language, it will be very hard to communicate.
Last, learning an Indian language would be a great choice in your spare time but it is not very useful real life, which is what most people will consider. If you are still in school, you may want to choose an Indian language but find there isn't one. Also, if you go on business trips to India, most of the people in urban parts can speak English and that is more appropriate for business matters.