There are two type of eligibility criteria for taking admission in IIT and NIT. You will have to be in either any one of them. One is that you are in top 20 percentile of your board and second is you have scored above 75% from any board. If you are not lying in any one of them you can't take admission in IIT and NIT. But still you can appear in the exam, and if you score good you will have many good college options.

All the very best and good luck.

dear student

greetings

if you score good marks in JEE mains and advance but have 62% in boards then you might not able to get IITs because to merely appear in Jee advance paper one must secure top a position in top 20 percentile, however, your chances for getting NITs are clear because that does not depend on advance's marks.

thank you