Hello Neha,
Generally, all the exams for the clerical post in bank would demand 12th as minimum qualifications, so you can definitely give those exams.
But some banks ask for graduation degree as a minimum qualification to appear in the exams like IBPS PO, SBI CLERK AND PO, RBI etc.
You cannot apply for those exams unless you have a valid graduation degree.
I would suggest you to start preparing for the exams and fill the forms after you complete your graduation.
All the best.