Hi,

IIT, IIIT and NITs are one of the best engineering college in India which deal with students who want to make a career in technology. You can get admissions in these colleges through JEE mains and JEE advanced exams,and should have completed your 12th class with science branch and atleast 75% marks in 12th boards. 

I hope I was able to clear your doubt

Thank You

Hello,

All of these institutions are run under central government of India. 

IIT is Indian Institute of Technology and it is the best option among these three (some NIT's are better). Most of the IIT have great faculties, facalities and placements.

NIT's are National Institute of Technology and these are also run by central government. These colleges also have great placement, facilities etc. These two are prestigious institutions of India. 

IIIT's are Indian institute of information technology. These institutions have focus mostly on IT sector. These are newly opened institutions. And these also offer good placements but not as great as some IIT's and NIT's.