Dear student, don’t you think you are over qualified to become just a Probationary Clerk? If you do want to get into a Government job, try for an Officer level. There are other exams that are conducted for Officer level entry.
MBA in itself is a good field. So if you are pursuing MBA from a good institute and have good scores, you will rock at the campus placement interviews and chances are that you will land up with a better paying job!
Having said that, we would like to add that we don’t know anything about your background. If money is a criteria right now, take the job, but continue with your MBA side by side. You never know what happens in the future!