Well, brother I would say it is a pretty wrong question in itself.

As, forming of these colleges is itself from the entirely different sense of notion/concept.

NIT's were made to have a college in every state which stands out in that particular state and this is the college, where government allocates the maximum state fund

IIIT's were made because to impart special training to the students who are majorly enthusisastic about coding, programming etc

GFTI's were made to impart students to knowledge on a very specific domain like cotton textile etc.

So, all these colleges are best in their own sense. It is a matter, how you use them as per your interest!

Thank You 

Nit stands for national institute of technology. IIIT stands for Indian international institute of information technology. And Gfti stands for government funded techinal institute. There are 31 Nit, 23 IIIT, And 23 gfits. In general, NIT are superior than the other 2. Nit are much reputed than Iiit and Gfti. In short, NIT>IIIt>Gfti