CBSE 12th

Go for B.Sc or BA. It will be helpful for you in UPSC examination. You can get much more free time for preparation of UPSC. Subjects like political science, law, history, etc. Geography will be helpful.

Go thoroughly with the NCERTs of Standard XI and XII. Along with that, start solving as many as MCQs that you can. This will surely boost your confidence up.

Most of the law colleges require above 60% for admission along with a good score in their respective entrance examinations (if any, e.g. in Kerala -Kerala Law Entrance Examination /KLE). And it varies for different states. Mention which state you are from or which state you prefer to study in, and I'll try to help you.
I hope the answer was helpful.

You need minimum 75% in best 5 subjects to be eligible for admission in NITs or IITs.

Apart from MBBS, BDS is the next preferred course by medical professional.
Apart from MBBS, BDS, other options are also there like B.Sc Biological Science, Nursing, Agriculture and B Pharm.

After 12th, you can go for B.Com and simultaneously prepare for MBA and try to get in any top B-School of India and go for Finance specialisation. Else, CA is the most common option.

Graduation admissions will be done on the basis of 12th. So, wait for the board results to get declared.

All colleges are provided scholarship who complete the noms of scholarship.

Yes, you can join after 12th.
Some options are:
AAFT School of Cinema - :
Bachelor Degree 3 yrs Course - B.SC (cinema) + Diploma in Cinematography.
Masters Degree 2 yrs Course - M.SC (cinema) + PG Diploma in Cinematography.
CREO Valley School Of Film & Television -:
It is recognised by Bangalore University to offer Certificate and Diploma Courses in Film Making and Cinematography.
FTII Pune - : Three Year Post Graduate Diploma in Cinematography.