Dear Aspirant, according to me CSE Indian Institute of Information Technology (IIIT), Kottayam is better than IIIT Nagpur and IIIT Dharwad as the placement and research work are much better in IIIT Kottayam than the other two and also IIIT Kottayam is old and reputed. I hope you are clear now. If you have any other queries feel free to ask. All The Best!!!