Change Of Gas Connection Of Ioc — not allowing to change gas connection of IOC

Address: Deoghar, Jharkhand

A gas connection was in the name of my father , who recently expired. I want the connection to be changed in my mother.s name with the same distributor. The distributor is not allowing. Is it legally allowed to change the connection in the name of my mother for the aforesaid reason.
kindly tell about the existing rules.