See there will be south Indian foods in hostel but you may expect only 2/3 times in a week. I belong to NIT Durgapur. Every Thursday we get Idli and Vada in the breakfast. Sambar is there in lunch for 7 days. We get Uttapam on Sunday's breakfast. Don't worry about foods as there will be plenty of options in each meal. You will get Roti, Rice, curry and dal in lunch as well as in dinner as a common dish and with this there are multiple options for veg and nonveg students. If you want to get a list of foods of any particular NIT, you will get it on internet.

Hope you understand. All the best.