The woman had sustained about 80 per cent burns and was admitted to a private hospital in Jamshedpur, Additional Superintendent of Police of Mayurbhanj, Ashok Patnaik said.
Statements of the family members were being recorded and arrangements were being made to bring the body after post-mortem.
On Friday, Ramgopal Khemka, 55, allegedly attacked and outraged the modesty of the woman finding her alone at home. The woman's father lodged an FIR at Rairangpur police station.
As the victim warned him to report the matter to the family members, the accused set her ablaze by sprinkling kerosene, the complaint said.
The accused has been arrested and investigation is underway, ASP Patnaik said.
A case has been registered against him under various sections of the IPC and a scientific team also visited the site of crime, he said.
The woman married Ramgopal's son Avinash two years ago.
(With PTI inputs)
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)