The accused, identified as Hargopal, was later arrested.
The incident took place when the eleven-year-old girl was going from one block of the residential institute to another. The accused dragged her into a room and then sexually assaulted her, S R Nagar Police Station Inspector G V Ramana Goud said.
After the incident, the girl reported the matter to her parents and a case was registered under section 376 (rape) of IPC, following which he was arrested, the police officer said.