Engineering Entrance Exam

With low score in JEE Mains you will not get the good colleges as in government colleges but you can contact to private colleges.

There is no chance in NIT with this percentile in JEE Mains.

https://www.shiksha.com/b-tech/jee-main-exam
Here are the complete details of the JEE Mains exam.

Refer the link:
https://www.shiksha.com/college-predictor

You can get the following Colleges through JoSAA as under.
1. VNIT Nagpur
Further the following are the other colleges accepting the JEE Main paper-2 score are as under. Please apply through State Common Entrance Test Cell, Maharashtra State website if interested.
1. Sir J. J College of Architecture
2. Institute of Design Education and Architectural Studies, [IDEAS] Nagpur
3. Balwant Sheth School of Architecture (NMIMS), Mumbai (Own admission process).

Cutoff percentile will be above 85.

I don't think you can get any college through JoSAA. Try for private college or state government college.

Yes, chances are good. I think he will get CS in fourth or fifth round of JoSAA.

You can apply for it. Chances are very less but still you should try for it. You may get a seat in last rounds.
https://www.shiksha.com/college-predictor

Hi
https://www.shiksha.com/college-predictor
Use this link to know about the colleges available to you.