The attack on Vasudev Singh took place when he was sitting with advocates at the Collectorate Bar Association premises, said SSP Umesh Kumar Singh.
The advocates present there nabbed the seven intruders and thrashed them before handing them over to police, he said.
According to the SSP, Vasudev Singh, his son and two others have been named accused in the case related to the burning of his daughter-in-law in Syana area here on June 9, the SSP said.