Hello Lagan

Basically for top NIT's like Trichy, Wranagal or Surathkal one must need to get 280+ for CSE but as you mentioned that you belong to SC then it is little less than General. 

You need like 170–180+ score need for SC students. It may be vary depending on question paper and cutoff rank. And of course, you will get some advantage for being home state quota, if you have.