Engineering Entrance Exam

You didn't mention your category. Your chances are very bleak.

NIT-Raipur, Government Engineering College-Raipur, Government Engineering College Bilaspur, Government Engineering College-Bastar, BIT Durg, Shri Sankracharya Group of Institutions-Bhilai, Rungta Colleges of Engineering and Technology-Bhilai and OP Jindal University-Raipur are the top colleges in Chhattisgarh.

I advise you to go for a drop, attend coaching and reanalyze your progress. JEE Mains and Advance has tough competition. Also, side by side explore your interests, i.e. do some short courses related to your interested field. If you opt for CS in future do learn C programming along. People are moving away from engineering due to limited job, if you end up taking mediocre college you'll regret. A gap year will cost you but will tell whether you are made for engineering or not.
B.Sc. now-a-days is also good option, academically as well as in terms of opportunity.

According to many students Vibrant Academy, Kota, Rajasthan.

You can get NIT-Sikkim.

No, ISM-Dhanbad does not take students through WBJEE.

Yeah, you will get NIT if you have any reservation.

It depend on the marks.

You can get MBM-Jodhpur, UCE-Kota but you must try top private universities such as BITS-Pilani, VIT-Vellore, Manipa-Jaipur and VGU-Jaipur.

You can get NIT-Sikkim. Try some of the best institutes such as VIT-Vellore, Manipal, SRM, VGU Jaipur, Amity, etc.