Hello Aspirant.......

Well securing 78 percentile in Jee Mains may not be able enough for getting admission into any of the NITs. But still you must try at the time of counseling since you're a ST candidate. Also applying for an NIT in your own home state can be beneficial as the chances of getting admission are more. But you may get other streams like basic sciences or integrated courses in NIT BHOPAL, NIT JAMSHEDPUR, NIT ARUNANCHAL PRADESH and many more.

Hope this helps you out......
Best of luck:)