How marks I have to score for NIT delhi?

It depends upon the JEE Main and JEE Advance cut offs, If You manage to qualify the exam by achieving the cut off, You can apply for JOSAA Counselling. It should be noted the cut off for EWS/SC/ST/FEMALES/OBC category is lower than the general category
However It is usually advised to fill the choices as per the preference of colleges and departments, for example CSE in NIT Trichy is your priority followed by CSE in NIT Warangal, you can fill CSE at NIT Trichy at serial number 1 and CSE at NIT Warangal at serial number 2 and so on and so forth. However to get any NIT, you must have qualified JEE Mains and to get any IIT, you must have qualifies JEE Advanced

But the previous cut offs of colleges should be taken in consideration, it is better to research over the cut off of colleges then make a preference list of colleges and fill accordingly

For the college preferences and the courses provided by these colleges and to know which colleges participate in the JOSAA counselling, please go to the below mentioned link: https://engineering.careers360.com/articles/josaa-participating-institutes

For college prediction as per your marks and rank, please go through the below mentioned link:

College Predictor 2021 - Predict Colleges for Engineering, Medical, Law and More

College Predictors – Know your College Admission Chances Based on your Rank/Percentile, Home State, Caste, Gender, Exam Result & Get your Pe ...

NOTE: please check the official site of NIT DELHI for previous cut offs, intake capacity and all other information regarding admissions.

Hello Jatin,

You haven't mentioned which branch you want to get into, whether you belong to home state or other state, and also your category. Please note that the miniumum marks would vary depending on each of these factors.

Also, the minimum marks or cutoff is not static and varies from year to year depending on variable like number of applications received for admission, number of seats available, and also reputation of the institute.

I would suggest you check this link for full subject-specific cutoff - JEE Main Cutoff for NIT Delhi

Regards.