I’m pursuing an MBA from an average college but will it be a good idea to take up an MBA again from IIM-A/B/C for better exposure and a good placement?

Work after you MBA. Do an executive MBA, EPDGM, after a while from IIMs. Your career graph shoots after an executive degree. I have seen people reaching the Directorial level or Business Heads of the country after a degree that way! Much better than doing MBA again. Monotonous.