Hi dear ,

              Admission in colleges accepting JEE main 2018 depends on rank of the candidate and cut off of the institute. These institutes include NIT's ,IIIT's,GIFT's and other state government colleges and universities accepting JEE mains score. 

You have good rank in OBC category so you are  eligible for any above mentioned colleges thus you can get admission if you do some research and see previous year cut off ranks different NIT's .

All the best.