The man was handed over to police by neighbours, police said.
A 21-year-old woman was allegedly pushed off the balcony of her house by a man, after she "refused" to accept his marriage proposal in outer Delhi's Mongolpuri area, police said on Tuesday.
The incident took place on Monday around 6.30 PM when the accused, identified as 28-year-old Amit, forcibly entered the woman's house with his sister and started fighting with the woman and her family, they said.
Amit allegedly threatened her to accept his marriage proposal but when she refused, he "pushed" her from the balcony of her house in Avantika Enclave in a fit of rage, said a senior police officer.
The woman was rushed to Baba Saheb Ambedkar Hospital where her condition is stated to be critical. The man was handed over to police by neighbours, police said.
Amit, however, claimed that the girl had borrowed Rs 1 lakh from him and wasn't returning it, police said.
Amit had apparently befriended the woman on Facebook around two years ago and the two got into a relationship, he said.
When the parents carried out a background check on Amit, they found that he was unemployed.
However, Amit kept pressurising the woman and her family for marriage.
"According to Amit, he had gone to recover his money from the girl and in order to shift the blame on him, she jumped off the balcony," said the officer.
The girl's family had lodged a complaint with the police before the incident alleging that Amit had threatened to create a scene in front of their house if they didn't return his money, he said.
Police is waiting for the girl to recover so that her statement can be recorded.