You have just passed class 12 with science branch. You have many choices after class 12. Now it depends on your interest. Please go through the below list of courses available after class 12 pcm. You can choose any one of them based on your interest - 

• Engineering
• Architecture
• Merchant Navy
• Commercial Pilot
• bachelor of science
• Railway Apprentice exam
• Business administration and management studies
• commerce
• arts and humanities

Hello Aspirent
What course you should choose it's totally depends on your interest . You should decide by yourself .
If you have interest on technical field then go for the engineering.
If you have interest in upsc and other government job then you may choose BSC , BCom , BA as career .
Thanks