Dear aspirant,

As you have mentioned that if you will join nit and next year you want go for IITs so let me tell you that if you have passed your 12th in 2021 so definitely you can give jee advanced for the next year but if you have not passed your 12th in 2021 and you have passed it in the year 2020 then you are not eligible for jee advanced as consecutive two attempts are applicable for jee advanced.

For more information you can check out the link given below-

https://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ici=qna_answer