Free JEE ADV-13 Course
I think you can get chemical,chemical science,civil in IIT guwahati under obc category
and you will also get computer science ,electrical ,mechanical in new IIts .This will be the best option for you.
Please feel free to post as many doubts on our discussion forum as you can.we will get you the answer and detailed solution very quickly. All the best. Regards,Askiitians ExpertsBadiuddin