The accused, including BJP MP's son, Muthu Sanna Fakirappa, were arrested last night and sent to judicial custody till December 30, police said.
The arrest came after an FIR was filed against them on the basis of the complaint by the girl's mother, they said.
Muthu and his supporters also thrashed a boy.
The girl's mother alleged that Muthu and his supporters visited her house situated in Fort area when her daughter was all alone.
"They barged into the house and started assaulting the girl, a college student, alleging she was engaged in prostitution," police said.
Muthu and his supporters also thrashed a boy, who had dropped into the house for a book, police said.