Your salary will be based on the tiering of your college. Students of better ranked colleges may earn salaries, from anywhere between ₹ 5-10 lacs per annum. It will vary from bank to bank & from college to college.
In general, an MBA degree will help your early career, only if it is from a reputed institution. The slight advantage in salaries that most MBAs get will be more than offset by the salary growth and real experience gained during those 2 extra years.