No, There is no subject wise provision for getting admission into NITs/IITs.

The board percentage criteria says that " A Candidate must have secured an aggregate percentage marks of 75% or should be in top 20 percentile of his/her own board. There is a relation of 10 % for the candidates of SC/ST category i.e., A SC/ST category student must have secured an aggregate of at least 65 % in his/ her respective board exams. "

Hope it helps.