The case was registered based on a note written by the woman at the hospital, detailing her ordeal, reported The Financial Express reported.
The woman was identified as 50-year-old Lalita Kayi.
According to reports, police suspect she was chained in the forest following a domestic dispute.
The shepherds, who visited the forest, reportedly heard her cries informed the police.
After an initial treatment, she was later admitted to a medical facility in Sindhudurg's Oros.
A top Maharashtra Police official told India Today: " The woman is not in a position to give her statement. The woman is weak as she has not eaten anything for a couple of days and also as the area experienced heavy rains. We don't know for how long she was tied to that tree. She reportedly left her husband after a quarrel."