Vikram, 32, attacked his estranged wife Suman and her family members at their home in Jaitpur area in south Delhi Monday late night.
He was annoyed over the second marriage of his wife, who got separated from him a few months after their marriage in 2009, said a police official.
Suman's father Om Prakash died of his injuries while Suman, her mother, two brothers and a sister-in-law were injured in the attack. The nature of injuries the family members have sustained is not clear yet.
Vikram also received injuries when he was overpowered and attacked by people.