What is the difference between NIT(national Institute of technology) and IIIT(indian institute of information technology)
Both are government and top level engineering institutes of India.
IIT - Indian institute of technology
NIT - National institute of technology
NITs take admission through JEE Main rank And IITs take admission through JEE Advanced rank. There are total 31 NITs with approx. 18K seats and 23 IITs (Including ISM) with approx 10500 seats .
You can understand the difference between IITs and NITs from the below points
1- Quality of Education: When it comes to the quality of education provided IITs are ahead of the NITs. Both IITs and NITs are extremely good in providing education and producing good engineers, but at the same time the top IIT colleges have an edge because of their high standard of studies.
2- Production of young leaders and founders: The research conducted in the US proved that IITians are among the leading founders of the top startups in America. IITs are the only non US university with most number of founders of companies in the US.
Flipkart, a leading e-commerce was established by Sachin Bansal and Binny Bansal, who were IIT-Delhi pass outs. Arjun Malhotra is the co-founder of HCL Technologies and is an IIT-Kharagpur graduate. Simply 360 is a social media monitoring and analytics platform which was founded Bhupendra Khanal, who completed his studies from NIT-Durgapur. Microland technologies was started by Pradeep Kar, who completed his education from NIT-Nagpur. The way of education and approach is also better in IIT, but it doesn't mean that IITs are not good. Both NITs and IITs are extremely good in providing education and producing good engineers, but at the same time the top IIT colleges have an edge because of their high standard of studies.
Hope it helps.

Let me tell you the difference between the two here.
Since both the institutes takes admissions via JEE Mains and there admission process goes at par through JOSAA. For CSE, Top merit candidates usually go for old NIT's like NIT trichy, warangal, surathkal, calicut, allahabad etc rather than IIIT's. I can't question there choice because these institutes really possess a good coding culture and healthy environment to excel & there students even get awesome placements. But if you get a choice to take between these NIT's & IIIT hyderabad then without thinking much choose the latter. Reason being simple that IIIT Hyderabad (International Institute of Information Technology) is one of the best in India for CSE. It's academics also outmatches some of the old IIT's. Provide better exposure than NIT's & average placement is way better than them. IIIT allahabad is also a very good option in this case.
Hope this helps you and I am again sorry for the inconvenience.