Ofcourse you can change domain from iT to banking. It may be bit difficult but not impossible. Prepare for IBPS exams fully and be eligible for 19 PSU banks. Also there are lots of pvt. banks you can apply for.Best of Luck.
Make sure that you have good interest in BFS, it wont be a good idea to gain scattered experience on multiple domains which wont be considered as a relevant experience on your profile.