Hospital sources said the 18-year-old actress, who is in the intensive care unit for spine and pelvic fractures and liver contusion, is unconscious and on ventilator.
Swarna fell from the balcony on Wednesday night and was in the Neuro ICU.
Swarna Thomas came to the limelight after participating in some dance reality shows of various television channels.
She is the actor in the film 'Buddy', shooting of which is in progress here. The actress has also essayed roles in a few other films, including 'Pranayakadha', 'Flat', and was to act in two Tamil films.