Hi aspirant

If you have intrest in banking sector then you must have choosen Commerce because while studying you would learn all the basic and fundamentals of bank related things like accounting and economics which you will lack in science stream.

Still there is a possibility .You can choose Accounts,Economics ,Business studies like subject in your graduation or either you can do BBA.If you still doesn't choose all these subjects then finally go for MBA or appear in the Bank exams like SBI PO,SBI Clerk ,IBPS.. etc

Good luck