B.Tech Ranking

Go through the link below for the list of probable colleges:
https://www.shiksha.com/b-tech/resources/comedk-college-predictor.

You can expect NITs since you are from SC category. Also some Tier 1 campuses like ITM and Jaypee. All these campuses have very good placement ranging from 4 LPA to 6 LPA.

I think u won't get government college. But try for jss akg or abes. A.

You must be asking about one particular college and seems to have typed incomplete question here. There is a process on Shiksha which will assist you to find a college as per your rank. This rank predictor compiles things for you:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor

Yes, you will get the colleges but not the top colleges. For more details, click on this link:
https://wbjeeb.nic.in/wbjeebcouns/orcr/PrevYearORCR.aspx
Here you will get all the information regarding all the colleges which are under WBJEE. Opening and closing ranks and branch-wise all the details are

That is entirely your choice. B.Tech is a technical qualification, professional in nature and basic graduation programme in engineering technology. B.Sc. Is a graduate course and is a basic programme in Science stream. Of course B tech has more value but much depends upon your college/institute, you