hi,

since nios does not provide character certificate, many universities accept admission even without a character certificate. if the university is not understanding your issue then you can just call the helpline of the university or go in person and just explain. nios is a government authorized so even after making fuss they have to accept your application.

though it will work, but if it doesnt then you can get a character certificate affidavit with a sign of gazetted officer. but ask the university if they will accept it or not before you get it.

hope it helped