Comparing brands like NSIT and IIIT is quite difficult . IIITs are established as primarily research institutes . For quality education , you should opt for IIITA . NSIT has its own advantages that other colleges cant provide .

• Locational advantage - DELHI
• Not much acadmic pressure.
• Coding environment is very good .
• Placements are better than IIIT-A
• Delhi University Degree
• Slightly better student population.                                                                                           

According to me both institutions are best but it totally depends on you and your comfort. For the time being I would go for NSIT over IIIT-A.