What kind of food is served at the mess? Is Jain food available?
There is SO MUCH variety of food available inside IIT Madras, so if you're thinking you'll only find the stereotypical idli-dosa everywhere you're wrong.
To start with, there are 6 to 8 messes at IITM serving both North Indian and South Indian food, including Jain food. Apart from those, there is a Food Court, several canteens and multiple restaurants serving all sorts of cuisines from chaat to biryani to burgers.
And if you're looking for even more variety, each IIT Madras gate is close to many good restaurants, of which Chennai has hundreds. Your taste buds will be thrilled at IITM, no matter what your preference or inclination.