The incident took place on Wednesday at Dyanodaya Vidya Mandir, police said adding that the accused Yogesh Pandit has been booked.
"On Wednesday morning, the girl was waiting outside the school along with the other students for the school to start, just when a boy came to her and informed that Pandit was calling her inside the classroom for some work," PSI S S Kulkarni of the Vartak Nagar police station said.
When the victim went into the classroom, there was nobody except the teacher. "The accused asked her to help him arrange the answer papers lying on a bech and then molested her," he said.
Further probe is on.