If I take admission in university affiliated college in my first year BCom, Is it possible to take transfer and take admission in an autonomous college?
Nope! If you have to take transfer to some autonomous college then you have to get admitted there as a fresher student of BCOM i.e., you have to take admission in 1st semester of BCOM again. But in case of Affiliating Universities, there are provisions to get transfer from one college to another college under the same university. By that way you can obviously do that but you can't take admission to any other distinct autonomous college, for that you have to cancel your admission in your affiliating college and then you have to take admission in other college.
I hope this answer helps. All the very best for your future endeavors!