Lạc was born in 1899. Lạc's father was H Con and his mother was Kiều. His paternal grandparents were H Viên and Từ Tâm Vũ. He had a brother and five sisters, named Thiện, Quỳnh, Dữa, Dữa Em, Đói and Gái. He was the third youngest of the seven children.