Police said the man, identified as Narendra, stabbed himself in neck with a knife this afternoon. His family members rushed him to a hospital in Lajpat Nagar, where he was pronounced dead on arrival.
The deceased's daughter told police that he father had been suffering from mental disorder for the past eight months and undergoing treatment.
Assistant Superintendent of Police Vipin Tada said a patrol van found Narendra roaming about on roads and dropped him at his residence late last night.
A case has been registered, the police officer said.