The woman, who was visiting a relative's place, was gangraped Friday afternoon inside an abandoned staff quarter of Kolkata Port Trust in Taratala area.
Sources in the Kolkata Police said medical tests confirmed gangrape.
"The incident took place at around 12.30 pm when a 27-year-old woman, who went to fetch chicken from a local shop, was taken to an abandoned house by a boy working there," the officer said.
Other accused men reached there while some of them raped her, others clicked photos and videos on their mobile phones, he said.
"They threatened her not to reveal the incident to anybody and left," he added.
The woman lodged a complaint with Taratala police station on the basis of which the six accused were arrested.
While three juveniles were sent to juvenile home, the other three were sent to judicial custody till February 3, the officer said.