Dear Aspirant 

Based on your obc rank it is very difficult to say that you will get CSE or ec in NITs or IIITs but if you wish chemical and civil then you can get these branch in Nits like kurukshetra, NITs Calicut, IIITs alhabad etc. But only in special round at the end. 

Good luck for your counselling. 

Feel free to ask if you have any further queries.