Hello Aspirant

Once you are admited to an institute, after filling out the forms and giving your fee, it is not possible for you to change your stream, especially after giving your exams. If you have mentioned the first year, I'm assuming you have appeared for at least one exam.

It can only be possible if you are in the initial days of your classes, maybe then you can go and talk to the administrative office of your college. Or you'll have to take a TC, refund, and enroll yourself in the desired stream, paying the fee all over again.

Right now, the best course of action would be to talk to the college administrators.