"Bhullar is still mentally unstable and he is being treated by a panel of five to six doctors," Rajesh Kumar, one of the doctors treating Bhullar at the Institute of Human Behaviour Allied Science (IHBAS), told IANS.
Kumar said that the panel treating Bhullar for the past two-and-half years has director of IHBAS Nirmesh G. Desai besides a doctor, a psychologist and a social worker as members.
"It is not easy to say that how much time is required for him to be mentally fit. We would share his condition with Tihar Jail officials," Kumar said.
The doctor refused to disclose Bhullar's illness.
The Supreme Court Friday rejected Bhullar's mercy plea. He was convicted and sentenced to death in 2003.
Bhullar had sought commutation of his death penalty to life sentence on the ground that there was an inordinate delay by the president in deciding on his mercy plea.
He approached the Supreme Court in 2011.