Dear aspirant, 

Hope you are doing well. As per your query there are many courses one can choose after class 12. If you are from science stream you can go for B.tech / BSc, if you are from arts then Ba and commerce then BBA/ B.com. These are just the mainstream courses. Can you please be precise about your choice and stream then I will be able to help you with the necessary information. Please feel free to contact with me in the comment section below. Thank you.

Courses after 12th Science with PCM:
Engineering (B.E/ B.Tech)
B.Arch.
B.Des Arch.
Integrated M.Sc Defence (Navy, Army, Airforce)
Bachelor of Pharmacy.
Bachelor in Computer Application.
Bachelor in naval architecture and ocean engineering.
Commercial Pilot course.
Best Courses after 12th Commerce:
Bachelors in Economics: ...
Bachelors of Business Administration (BBA): ...
Bachelor of Management Studies (BMS): ...
Chartered Accountancy (CA): ...
Company Secretary (CS): ...
Cost and Management Accountant (CMA): ...
Certified Financial Planner (CFP): ...
Bachelor of Law (LLB):.

Feel free to comment if you have any doubt
Good luck