The incident took place near Maharaja Agrasen College.
Two constables were on motorcycle patrol when they found as many youths on two bikes in suspicious condition, police said.
"When they intercept them, the youths - identified as Ahesan and Riyaz - fired at police. In the retaliatory action, a bullet hit Ahesan's left leg. The duo was overpowered by the constables," a police official said.