Hello Aspirant.

There are several decent or great institution you can get through JEE mains such as NITs or DTU or NSIT for for that you need to cross the eligibility criteria for JEE main which is scoring atleast 75% aggregate in class 12th for general and scoring atleast 65% in class12th for obc/sc/st. And you haven't cleared it so you won't be allotted with any college untill you fulfill it

Best of luck