CBSE 12th

Both are similar to each other with minor difference in electives. You may chose any based on Institutes reputation, faculty, facilities etc.

First of all congrats for completing 12th.
CA and CS are the best courses but maths is required for CA. You can do any other course like: B.com or BBA.In B.sc IT and BCA maths is required. But if you are ready to do hard work in maths then you will have much more options to choose.
Thank you
All the best

ur jee main score is good Bt 12th %age is too low. So u can check under 20 top NITs. U can also check IIITs. I.e. NIT Durgapur, IIIT Bhubaneswar etc

look only for private college

well you should do cse from ipu from mait if you really want to do engineering

Yes you will be able to get admission into this college (Maybe not in the CSE stream). Your rank should be around 20,000. You can get into the college, but if you want to pursue CSE, I suggest you try for the Integrated M.Tech. CSE branch here at NIT Hamirpur. Or, alternatively you can try for CSE at IIIT Una college, whose classes are being held at NIT Hamirpur only.

It is a matter of getting qualified first. Think of it. If you don't finish 12 th, you can't explain it in a job interview.

no idea .it will depend on cbse merit list.so wait for it