Bihar Chief Minister Nitish Kumar said strong action will be taken against the accused.
The men had apparently kidnapped the Class 10 student when she had left her house to meet a friend on Friday evening, the police said.
The local police said she has jumped off the train when she saw her family members searching for her at the station.
Later, when the girl was taken to the government-run Patna Medical College, there was a delay of six hours in admitting her, the family said.
The girl, who was allegedly raped by six men, was denied a bed in Patna hospital for six hours.