Hi, according to the website of jac the joint academic counseling the authority that conducts centralized counselling for admission in dtu,nsit, Iiitd the minimum eligibility criteria for admission to these colleges is that you have to score atleast 60%in your 12th board exams. After scoring atleast 60% your jee mains rank is considered and admission is done on merit basis. If you have 50%in board exams you are not eligible doesn't matter anything else.