Aryaman ;

The questions you've asked depends on two criterias. First is whether you're from Delhi or not. The other is whether you want a branch like CSE and IT (or) ME and EE . Depending on that the cutoff might vary. If you're from Delhi than your condition is better compared to other state candidates. While for getting into branches like CSE & IT you've to score a lot more compared to ME & EE.

Speaking of eligibility marks, you'll be allowed to take part in NSIT counseling process if you've cleared JEE main paper. Considering the 300 mark system if you wind up scoring a minimum of 100-110 you'll be eligible to clear JEE mains.

For more details on NSIT, visit this link

https://engineering.careers360.com/articles/jac-delhi

Hope this helps!