I have friends in other Thapar and NIT Delhi so I am the right person to answer your question. Based on their experiences, these are the key points of differences I derived
- NIT Delhi has a better location because it is in Delhi.
- Thapar has a better faculty pool and lab facilities than both NIT Delhi and NSIT.
- Thapar also has an active research culture so if you are a research enthusiast, Thapar is a better option for you.
- In terms of tag and brand name, NIT Delhi has the upper hand. Thapar University also has a good reputation but mainly in North India.
- NIT Delhi charges much less fees than DTU and NSIT so it’s the clear winner in this aspect.
- Infrastructure-wise, Thapar University tends to serve better.
Overall, it's a matter of preferences!