Congratulations on completing your 12th this year.
Some good things you can study and do after 12th grade are.
Bachelor of Technology (B.Tech).
Bachelor of Engineering (B.E).
Bachelor of Medicine and Bachelor of Surgery (MBBS)
Bachelor of Dental Surgery (BDS)
Bachelor of Pharmacy (B.Pharm)
Bachelor of Science (B.Sc)
Bachelor of Computer Applications (BCA)
Bachelor of Architecture (B.Arch)
You could also study to get your MBA, study for business administration, environmental science, design, graphics design, coding, physotherapy, Biothechnology, scientist, Bachelor of Journalism, Arts, Architecture, Pharmacy, Fashion design, Engineering, Dental degree, Bachelor of Arts, MBBS, Law, Bachelor of Commerce, Bachelor's degree, therapy, Hospitality management.
It all depends on what you are interested in.