CBSE 10th

Yes, you are eligible.
(A) The first year of post SSC.
(i) The candidate should be an Indian national;
(ii) Passed secondary school certificate (SSC) or its equivalent with at least 35% aggregate marks.
(B) Direct second year of Post SSC.-
(i) The candidate should be Indian national;
(ii) Passed higher secondary school certificate (HSC) in science or HSC in science with vocational or HSC in science with technical or SSC with 2 years of ITI with appropriate specialization.
Kindly visit the link mentioned below for detailed information:
dtemaharashtra.gov.in

Yes, but you need to take admission in a school and pass class 11th.

Graphic Era-Dehradun accepts students with 45%. So, yes, You can easily get admission. But you will need to spend a good amount of money.

There is no minimum score as such (B has >80% criteria, might have changed so do check)
Put in your best effort for CAT, all this comes later, and you anyway can't change your scores.

If you want to become an officer, you must have a UG degree. It can be BA or engineering.

Dear,
For this programme, you should pass class 12th with a minimum of 70%. You cannot pursue Bachelor's degree after completing class 10th.
All the best.

There are various options. You can opt for Diploma in Engineering or an ITI or you can also go for +2 (intermediate) in either science, arts or commerce stream depending upon your choice and future goals.

First clear 12th and then only you are eligible for any engineering program, you also need to make yourself strong in physics, chemistry and mathematics as these subject has greater role in your selection to engineering program as well as understanding and succeeding. There is no other way or shortcut.

To pursue BBA, you need to complete class 12th.