Police said that the girl hung herself from the ceiling of her house in suburban Powai on Monday evening after returning from school in Kurla.
"Family members, who entered the room in the nick of time, managed to rush her to hospital but she died while under treatment," an official said.
Police said that no suicide note was found but her parents alleged that she took the step because a teacher had scolded her after finding chits in her answer sheet.
"When the girl was submitting her exam paper at her school in Kurla, the teacher found some chits in the victim's answer sheet. She allegedly accused the girl of cheating and scolded her," police said.
Officials said that a case of accidental death has been registered and further investigations were underway.