Police said the incident happened last night when the constable, Bharat, was partying with the victim, Mohammad Aslam, after getting a new motorbike.
A case under section of attempt to murder has been registered against Bharat. Aslam has been admitted to a hospital and is said to be out of danger.
Police said the constable was earlier posted with the Preet Vihar police station. "He was suspended a few months back and sent to district lines," an official said.
Police is looking for Bharat who is absconding since the incident.
