Hello,

The sole purpose of doing MBA by joining IIMs is simply the pay package and the career advancements that candidates aspire for, it's prevalent in MNCs only in India as well Internationally, there are of course recruitments done by PSUs, or even in banking sector of public and private  for MBA graduates,  there are also IIM graduates who appear for UPSC CSE, it's a very individual choice what one prefers to do after passing out from IIM, but most common reason for MBA is working in corporate world, or some have their own start-up, so this varies among individuals and their aspirations.