Class 12-science

If you wish to dropout an year, give yourself a final chance. If you clear NEET that's well and good, if not try for private colleges. MBBS is the only course you want to enroll for, then try to get minimum 50% marks which makes you eligible for admission in any college whether it be private of government. or you can do BAMS or BHMS as per your convenience.

There are potentially hundreds of courses which you can pursue after class 12. Make sure you keep your grades up so that you qualify the minimum criteria for admissions in most institutes. Refer to th link provided below for a list of careers which you can pursue after class 12. Select a course and pursue it. Pursue a course you feel comfortable studying. and where your interests lie.
https://www.shiksha.com/careers

Eligibility for B.Sc. in Genetics
The basic criterion of eligibility needed to be met for admission to the course is a Higher Secondary (10+2) or equivalent qualification from a recognised educational Board, with Physics, Chemistry and Biology as main subjects and a minimum aggregate score of 50%.
B.Sc. in Genetics: Admission Process
Admission to the course is based on the candidates performance at the 10+2 level. A few institutes however, shortlist students based on their performance in an additional entrance test conducted at their own level.

You can go for B.Sc or law or Army/Navy/Air force and many more options are available.
The point matters that what is your interest.

Eligibility for B.Sc in radiography
The basic eligibility criterion for admission to the course is a 10+2 or similar qualification from any recognised educational board with physics, chemistry and mathematics as main subjects. Some institutes require a minimum aggregate score of 50% in classes X and XII as an additional criterion of eligibility.

You should definitely be a teacher. Pick a subject you are good in and pursue it. If you like explaining things and making others understand a topic, you are truly gifted. Please refer to the link provided below for a list of careers which you can pursue after class 12. Select the stream you want to pursue and pursue it with great conviction. Good Luck!
https://www.shiksha.com/careers

After 12th with science, you need to pursue a Bachelors in your field like BE or B.Tech or equivalent degree. Only then you can apply for MBA.

If you are from General category background, then you have already crossed the upper age cap (25 years) for appearing in JEE Mains Exam. In that case, you do better. Go for AMIE, which is equivalent to B.Tech.

Yes, it depends on candidate's interest. As of now, you can pursue B.Sc. Some colleges offer BBA, BCA, BCS, BFA, and Fine Art.