This is one of the most confusing periods to select the courses after 12th. First, you should counsel yourself. Suppose that;
You have chosen PCM stream or PCB stream or Commerce or Arts in 12th standard. It means you have chosen your area of interest. Do not surprise or tense. You have done your best. But yes, of course, if you wish to change your field for higher studies, you can go through many options according to your interest.