Netaji Subhas University of Technology

You should go according to your branch of interest. You need to opt for the field in which you are mostly interested because both the colleges are very good. If you don't have any branch issue then go for IIIT-Delhi.
Best of luck.

Hello dear,
If you want to get admitted into NSIT then you must have appeared for JEE Mains and secure a good rank in JEE Mains too. After getting a good rank in JEE Mains, you have to fill a separate form for counselling JAC Delhi. In order to take admission in NSIT, you have to appear for JEE Mains then you have to participate in JAC Counselling. This year cut-off rank for All India level is 4867. You need to score above 60% aggregate in PCM.

Hello dear,
If you want to get admitted into NSIT then you must have appeared for JEE Mains and secure a good rank in JEE Mains too. After getting a good rank in JEE Mains, you have to fill a separate form for counselling JAC Delhi. In order to take admission in NSIT, you have to appear for JEE Mains then you have to participate in JAC Counselling. This year cut-off rank for All India level is 4867. You need to score above 60% aggregate in PCM.

Hello dear,
If you want to get admitted into NSIT then you must have appeared for JEE Mains and secure a good rank in JEE Mains too. After getting a good rank in JEE Mains, you have to fill a separate form for counselling JAC Delhi. In order to take admission in NSIT, you have to appear for JEE Mains then you have to participate in JAC Counselling. This year cut-off rank for All India level is 4867. You need to score above 60% aggregate in PCM.

Hello dear,
If you want to get admitted into NSIT then you must have appeared for JEE Mains and secure a good rank in JEE Mains too. After getting a good rank in JEE Mains, you have to fill a separate form for counselling JAC Delhi. In order to take admission in NSIT, you have to appear for JEE Mains then you have to participate in JAC Counselling. This year cut-off rank for All India level is 4867. You need to score above 60% aggregate in PCM.

You can go the college predictor link: https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor to know about the college you will get.
Good luck!!

Yes may be in 3rd, 4th or in spot round, you may get a branch.

Almost impossible in spot round also.

Speaking unbiased, if you want to pursue computer engineering prefer NSIT over DTU or if any particular branch which is there in NSIT and not in DTU and you have keen interest in that branch. But for any other branch prefer DTU. DTU has a bigger brand name than NSIT though both are equally good more or less. NSIT is good in terms of discipline but campus life is better at DTU. Opportunities are more at DTU to work for yourself.

Mention your CRL rank please.