Delhi

This question can't be answered because there is no mentioning of the course.

I think It was around 120. But I am not sure but the cut off marks was 220+. You can mail JMI's mail id or you can call or visit the campus if possible. It's about your career, do everything way it takes. All the best.

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

Your CRL rank should be under 3000.

Yes, you can. Outsiders can apply for sure.

Almost impossible in spot round also.

IITs, DTU and NSIT.

You can't just describe a college to be best upon the placements (reason I will explain below). Also the course structure of event institute are also something they are experimenting with the students at this moment.
So I will try to be very specific upon the topic about best institute. There are a number of institutions available with different courses in the market. The institute are like:
NAEMD
NIEME
MDI
Amity University, etc

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.