The incident occurred at 12.30 p.m. in Central Delhi's Barakhamba Road area.
Rakesh Kumar, resident of Dehradun in Uttarakhand, jumped off the DCM building.
"Rakesh fell on a pedestrian Mukesh, 44, who suffered injuries in the incident. He is being treated in a hospital," said a police officer.
Police has recovered a suicide note from the possession of Rakesh in which he had written that he came to Delhi from Dehradun in search of job but failed to get one, despite several efforts.