The attacker, identified as Kanwaljeet was nabbed by CISF personnel soon after the attack and handed over to police.
Nitin, who was injured in the incident was taken to Ram Manohar Lohiya hospital where his condition is said to be out of danger, according to police.
"Kanwaljeet attacked Nitin after an argument between the two at the door of the train. The train was overcrowded and it is not clear what caused the altercation.