Engineering Entrance Exam

Your chances are low to get this branch. But you can try through management quota.

Yes, you will be getting the call letter since the college sends call letter to almost all students. But they are not provided by the branch the students want and also you may get another branch, other than the main branch. So you may not be getting the branch you want or the campus you want.

It is required at the time of admission.

Since you have secured more number than the cutoff and if you are from another category than general then your chances of getting IIIT or NIT is more. By the way you can get any branch in this university you want. I suggest you to work hard for JEE Advanced and try to get a seat in IIT.

Yes you can definitely get admission in SSIPMT, Raipur without giving CGPET, on the basis of JEE Mains you can get admission. CGPET is a university based examination and JEE Mains is an all India based examination so on the basis of that you can get admission.

You can take admission in private engineering colleges.

Last year's closing for home state in mechanical was 29862.

Yes, you are eligible for JEE Advance exam. For OBC category the cutoff is 45.

Yes, you have good chances of getting top NITs and other top engineering colleges. Check the below college predictor link for the NITs which you can expect:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=8030745

It completely depends on your area of interests, competitive exam in which you appear and the main criteria is your Rank and Marks. If you have scored good in exams you will definetly deserve a seat in reputed college which has good infrastructure and faculties along with decent placements.So all the best for future.