Dear Student,
Glad to hear that you're sincere about your career and it's future aspects. Following are some major career options for science students after completing their 12th :-

• M.B.B.S :- If you have interest in becoming a doctor you can surely pursue it by appearing for NEET and clearing the cutoffs.
• Bachelor of Science (B.Sc.)
• Bachelor of Homeopathic/Ayurvedic/Unani Medicine Surgery (BAMS / BHMS / BUMS)
• Bachelor of Dental Surgery (BDS)
• Bachelors in Biotechnology
• Bachelor of Veterinary Science & Animal Husbandry (B.VSc & AH)
• Bachelor of Pharmacy (B. Pharm)

Hope this might help you.