I am a final year B.Sc student, but I am facing difficulty in studying B.Sc. Can I pursue one-year BA?

Hi, You can't change your course in the final year. You will have to complete your B.Sc to get a graduation degree. Work hard and try to clear all the subjects in B.sc and after Graduation you can choose other stream.

There's nothing like such one year BA. You have to start right from the beginning if you want to pursue BA.