Dear Antima, most banks require you to have any Bachelor's degree. SBI is one among them. The minimum qualification to be eligible for  IBPS is also a Bachelor's degree. So any Bachelor's degree will do. But to complement working with Accounts, few Candidates pursue B.Com. Having said that even non commerce graduates also crack IBPS and secure jobs. There is no bank course after 12th per se. You need to complete your Graduation join any training instititution for preparation.