Police said that the security guard of Kalyan apartment found the girl lying in a pool of blood on the rear side the building.
The girl was rushed to hospital, where she succumbed to injuries.
According to the security guard, the victim had gone to meet Monu Singh, an employee of a private bank, in a flat on the seventh floor of the apartment.
A senior officer said, "The guard told that the victim entered the apartment with another girl. It seemed that the girl was first raped and later thrown from the seventh floor.
The guard said that he saw Singh leaving with his friend Sahil in his car in a hurry.
The police later searched the flat and found beer cans along with cigarettes.