IIIT Delhi ECE anyday is better than BITS Hyderabad ECE or even BITS GOA ECE. It has really come up very well with very good reputation abroad because of good faculty,curriculum and placements. I had the same options as you last to 2 years back and I chose IIIT Delhi and don’t regret it.
Do compare the faculty,placements,etc of both the colleges. IIIT Delhi has the highest average BTech package this year also(11.67 lakhs).
But If you are looking for only campus life and chilling out in college then IIIT Delhi is not the place.
All the best !