Colleges in Assam

Sorry, it is not possible. Your marks are too low. You have to score around 120 marks in JEE in general category to get a good stream.

It's better to go for ECE from NIT-Silchar rather to go for chemical from NIT-Raipur.
As both the colleges are not topped ranked NITs, so here branch matters more than the college.

Hi,
Other than IITs and NITs there are many private universities like VIT, SRM, BITS, Galgotias, Nirma University, UPES-Dehradun, Amity, Sharda and LPU which are having high placement records and the decorum here will make your personality develop.

Last year, total 46 students opted for placement and 29 got placed with average packages of 6.9 lakhs.

Hi,
The best way to predict a college through JEE Main score is by using Shiksha college predictor.
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor
It shows accurate results.
After that, just go for the counselling of that college.
Best of luck for your future.
Keep asking

Revise your B.Sc subjects thoroughly with special focus on microbiology, questions from all subjects such as cell biology, chemistry, immunology, biochemistry, etc. are asked only basic understanding. The Entrance Examinations for various PG, UG and Integrated Courses will consist of a Written Test of 50 marks of one hour duration and a personal interview of 25 marks.

If you want to end up with your core subject as mechanical then prefer it first but as per the campus ranking IIT, Kharagpur is better than Guwahati but I'd suggest you to do mechanical from II, Guwahati.

No, you won't be deemed eligible for admissions into IITs because you haven't qualified the cut-off set for OBC category was 64 and your score is below that. So, you can't get admission in IIT.
Explore other options and don't worry, it's not the end.

Admission in B.Tech at NIT, Silchar is based on JEE Mains score.