The incident occurred late last night when she was sitting on a parapet wall of a building opposite the rented accommodation she was staying in, and after her fiancee had gone to fetch a glass of water for her, they said.
The man and his neighbours immediately rushed her to a hospital, but she succumbed to injuries, they said.
The 23-year-old woman, a native of Jharkhand, was an operations executive with Infosys Technologies Limted for the last two years and was staying in a rented place in the city.
Police said the full facts would be known only after the post-mortem, which would be conducted tomorrow after the woman's parents arrive from Jharkhand.