How can I get admission in colleges in Rourkela for B.Tech as I haven't applied for IIT JEE?

You can take admission in any private college for B.Tech. Stay aware & updated about state level counseling in your state, on the basis of your board marks you will get your seat there.

You can get admission by giving some private universities entrance exams like BITSAT, SRMJEE, VIT, Manipal, BVPCOEP and lot of others are there, so don't worry, just prepare your concepts and select the exams which you want to give.