You can take admission into various colleges that you they are good for your BTech course. Unfortunately, You will not be able to get any government college as for NIT you need 75% and even your JEE MAINS is not cleared so you will be able to get admission into some limited colleges only. 

You can check for various colleges branch vise at JEE MAIN COLLEGE PREDICTOR as being provided by Careers 360 only at very nominal price and then you will be able to see various colleges and you can apply in best college according to your needs. This will be really helpful.

https://engineering.careers360.com/jee-main-college-predictor?icn=jee-main-clgpd_landing-page&ici=prediction-section_c360-home