Engineering

Hello there,
Both are carrying good scope in their respective field. Its up to you what you like more engineering or B.Sc Maths. Engineering is creative application of Science maths, innovations design, construction operation of machines, etc. And B.Sc. Maths is a undergraduate programme related to m

Wait for another year or take admission in a different college. Weigh your options now. What would be best for you, waiting or pursuing the degree from different college.

In private colleges, you can get admission. In state governed colleges, you can also get that but getting central governed colleges it will be difficult for you to get that.

Yes, you can if you have passed 12th or maybe, you can reappear for 12th along with giving JEE.

SET will be available anywhere in the month of January next year and will be available till April:
https://www.set-test.org/how-to-register-set-test-application-form.html.

Yes, you can get your full money in refund if you don't get a desired college.

Depends on the college you are seeking admission in. But you are probably eligible for most. Some universities require you to pass a certain exam or test and selection is based on the performance of that test.