What should I opt for IIT DELHI Civil or IIT KANPUR Economics
I'll suggest you to choose Civil Engineering in IIT Delhi over Economics in IIT Kanpur.
As Civil Engineering is a core branch whose scope can never be ended from the market and IIT Delhi holds much more reputation than IIT Kanpur.
You'll also get a decent college/hostel life in Delhi as compared to Kanpur.
For more details about IIT Delhi, click on the link given below:-
https://www.careers360.com/university/indian-institute-of-technology-delhi/amp
Hope this helps.
Best of luck!!