Rajat (29) was shot dead by a group of men outside his house in Sangam Vihar Colony here last night, police said.
The deceased had attended his friend's engagement party where he got into an argument with some guests at the function, they said.
The argument heated up but other guests settled the matter, they said.
However, some of them later went to Rajat's house, beat him up and then shot him, they said, adding, he died on the spot.
The deceased's father has registered a case against several youths, including one Chintu, in this regard, they said.