The girl, hailing from Darjeeling in West Bengal, was brought to the city by the family from Assam, who runs a consulting agency here, they said.
She was allegedly beaten by the couple, police said. As the girl fell unconscious on Thursday, she was first taken to the National Institute of Mental Health and Neurosciences by the couple and was later shifted to a private hospital, they said.
The girl was later shifted to the government-run Vani Vilas Hospital police said, adding, "she is now out of danger".
The couple was arrested on Friday and booked under various sections of IPC, including 326 (voluntarily causing grievous hurt with dangerous weapons or means), they said.