Five have been arrested, police said.
The arrested men chased Aryan Mishra and his friends, including two girls for about 30 kilometers in the Delhi-Agra national highway.
The cow vigilantes had got an information that a few cattle smugglers were recceing the city and picked up cattle in Renault Duster and Toyota Fortuner cars.
After noticing a Duster car, the chasing group asked one of the men who were chased to stop the vehicle.
After the car didn't stop, the group chased the vehicle, opened fire and a bullet hit Aryan, who was in the passenger's seat.
When the car stopped, a second bullet hit Aryan's chest.
But when two girls were spotted in the car, the cow vigilantes realised they misidentified them as cattle smugglers.