In spite of its lower ranking, why has VMMC been occupied first compared to KGMU?

VMMC attracts a major crowd of NEET toppers. It is the most chosen college after MAMC. There are several reasons why many people choose VMMC over KGMU.

Mandatory rural service is the biggest disadvantage of KGMU. Those planning for a PG/superspeciality especially find this service period unnecessary and time-consuming. Moreover, VMMC is located in Delhi. This makes it more favorable. Though I personally feel Lucknow offers almost every facility. Internal PG reservation also works in the favor of VMMC. 

KGMU is ranked much higher than VMMC. The education at KGMU is much better too. Despite this, VMMC is preferred because of the above reasons.