The victim had woken up to go to the washroom when the three accused, who live with her and her family in a shared accommodation, gangraped her, police said.
The girl was admitted to hospital in critical condition, they said.
One of the accused, Sher Mohammed, was arrested, while the other two Shadab and Sahib, who are Sher's nephews, are absconding, they said.
Family members of the girl have alleged that the accused also tried to kill the victim by strangulating her, police said.