The fees structure vary from Institute to Institute. You need to mention in which IIIT you got a seat. Here's some of the IIITs fees structure mentioned below:

IIIT: Gwalior: 5.6 Lacs.

IIIT HYDERABAD: 5.4 Lacs

IIIT Jabalpur: 6.2 Lacs

IIIT Kancheepuram: 5.3 Lacs

IIIT Kurnool: 5.25 lacs

It can be assured that fees structure in every IIITs are in between 5.5 to 6 Lacs for 4 year b.tech programme. Hope it would be helpful.