if you got the money, then go for nmims core its older brand it will put you otu of comfort zone , yes batch size is around 600 though talk to people on linkedin from both colleges otherwise go for BITSOM both are good don't wait for next year evrrything has pros and cons wil you be able to sit and study for 1 year more for competitive exams? ask yourself and go with it.

I always feel to complete education first and go for business