The woman (22), hailing from Dehradun, was allegedly raped by three men, including an auto rickshaw driver, on November 17, they said.
She had taken the auto rickshaw after attending a stenography class from sector 37 here.
One of the accused, identified as Mohammad Irfan, was arrested while two others were still at large, the police said.
"Irfan had pre-planned the rape along with his two other accomplices," Superintendent of police Jagdale Nilambari Vijay said.
The two other men were already sitting in the auto, as per a complaint filed by the woman, the police said.
The three men dumped the victim in sector 53 after allegedly raping her, they said.