firstly you need to understand the difference between IIT and NIT and other government institutes and private institutes the first and foremost difference between IIT and others is the brand nameassociated with IIT which make IIT the first choice for all the multinational companies. You will find almost all the companies which are recruiting in NIT are also coming to IIT but not vice versa.in terms of packages the lowest package offered it it is generally more than 7  ,8 lacs per annum. In terms of core engineering knowledge I don't think that there is a big difference between IIT and NIT students in fact there maybe many NIT students who are very good in core engineering knowledge compared to IIT students.

One important things to not that not all IIT and get better placement compared to NIT students there are many NIT students who got very good salary compared to IIT studentsn. Most of the companies visiting IIT is also visit a NIT so there is nothing to worry much about it provided that you are good at what do you do.

IN SHORTS YOU CAN GET VERY GOOD PACJAGE AND PLACEMENTS AT NIT,BUT  YOU NEED TO WORK ON YOUR SKILLS AND CORE ENGINEERING KNOWLEDGE.  IF YOU ARE ASPIRING FOR HIGH PACKAGES THEN CHOOSE CODING PROFILE.