Is it acceptable in nit if I am passed class 12th privately or through nios?
Yes definitely it is acceptable, but you will have to secure a minimum criteria marks which changes from board to board.
For example, for CBSE it is minimum 75%.
So,
Good luck...!!
hi aishwarya
yes it is acceptable . you can give jee mains exams whether you are a private school student or nios ,and can be selectd in any of the nits as per your jee mains rank. you will be treated same as other candidates but i have heard(not confirmed) that a nios candidate have to give the jee mains exam only in some of the nios centres but this is not a big deal
best wishes