CBSE 12th

You can do BBA, BCA (If you had maths in 12th), BBM, B.Com, etc.
These above-mentioned courses are job oriented courses.
Good luck!

If you really want to pursue your career in aviation and will be satisfied with your life if you get a chance in it, then do it rather than regretting the whole life that you didn't achieve what you really wanted. But as you have lost the basics of maths, focus on it more and join a good coaching or better hire a good maths private tutor so that you will face no difficulties while practicing it.But you have also mentioned regarding your interests in biology. So be wise in making your decision. See what interests you more and will make you happy.

What is your stream? From which board did you complete your SSC?

Sir, I think you should decide this according to his interests and abilities rather than imposing your own decisions on him.

Which course do you wish to pursue?

Hello,
Kindly go through this link:
https://www.shiksha.com/mba/resources/iim-call-predictor
Good luck.

There are lots of courses after graduation:
Sales and Marketing
Management
CS/ CA/ CFA/CWA
Computer Courses: MCA/Animation/Web Design
Mass Communication And Journalism/Advertising
Hotel Management
Travel and Tourism
Civil Aviation: Air Hostess/ Commercial Pilot
Social Work
Law
Banking & Finance
Library Science
Teaching: B.Ed
Designing(Garment/Jewellery/Foot Wear/Interior designer)
Content/Technical Content Writing
BPO/KPO
Entrepreneurship
MBA Courses
Animation Courses
Banking and Finance Courses
Computer Courses

Most of the colleges have eliminated the GD process and replaced it with WAT(Written Ability Test) which is more of a test of your thought formation and english writing skill and not just about having the highest voice in a fish-market. But PI still remains the most integral part of the process. Hence if you feel that you are not confident enough in English, I would suggest you work hard towards it and if required join a coaching center for the same and overcome your hurdle.