Well certainly NSIT is a better college with all round development aspects and a huge alumni to support placements as compared to IIIT Delhi which is a fairly new institution.

Computer Science with specialization in Artificial Intelligence is being launched for the the first time in these institution. Anyways one can expect them to be somewhat similar to the core computer science syllabus with some courses and labwork focusing on AI.

Previously students had to choose from departmental electives for learning such subjects such as AI, Big Data manipulation, Network Security etc so it would be better to have a current course work outlined for the same. Many institutions are also starting Mtech in AI because it is a promising field.

Anyways IT is relatively a branch with lesser course load so you get more time to discover yourself in college.

So NSIT CSAI>NSIT COE>IIIT CSAI