Both of the institutes are located in Delhi, so location is not the issue. Both are visited by top management companies like Bain and BCG. Honestly speaking, Civil Engineering will limit your chances to go for tech companies like Microsoft, DE Shaw, Cisco, and Google. However, for Quant profile, IIT Delhi is the best with top banks such as JP Morgan, Morgan Stanley, and Goldman Sachs.
Both institutes have access to coaching institutes for preparation for Civil Services or MBA but IIT Delhi has a much better location. Basically, both institutes offer a heterogeneous mix of facilities and opportunities.
Why should one go for NSUT?
IIT Delhi Civil is a bit inferior in comparison to NSIT, as TPOs mostly comprise Tech Companies that are open for circuital branches like CSE, EE, ECE, M&C, and Instrumentation. Moreover, IIT Delhi has a better crowd and thus more competition during internships and placements. The core placements in Civil are pathetic and most students opt for non-core placements.
Why should one go for IIT Civil?
Conclusion
If you are looking for internship opportunities right after graduation, NSUT is the place for you but if you are ready to pursue a slow but stable career with a great scope for growth then IIT Delhi Civil is a good choice for you.