Admitted to a private hospital for over 45 days, she was put on ventilator support yesterday.
"She is on ventilation and dialysis. Her kidneys and lungs are not functioning properly," doctors at the Belle Vue Clinic hospital said.
Bacteraemia, bacterial infection in the blood, has also increased now, the doctors said.
The 90-year-old writer-activist, who is known for her dedicated service for the welfare of tribals in different parts of India, is suffering from multiple age-related ailments and has been administered antibiotics and given renal support.