Anshul Gupta, a student of St John's High School, was beaten up by his teacher Rupam Gupta for gossiping with friends in the classroom, the police said.
An FIR lodged by his father Banshidhar Gupta at Golabari police station alleged that Anshul suffered injury in the neck and is admitted to a local hospital.
The accused teacher is absconding, police said.