The incident occurred at about 9 AM when the man, identified as Rohini-resident Jayram, jumped on the tracks as a Rithala-bound train was coming.
Officials said CISF and Delhi Police personnel reached the spot but the man had succumbed to his injuries by then.
The operations at the station were briefly held up after the incident, they said.
His body was shifted to a nearby hospital where a post-mortem was conducted and his family informed, officials said.
The police is probing the reasons for the suicide and registered a case, they added.