The incident took place near Bamangam village of Padra Taluka yesterday in which the Jain nun, identified as Sadhvi Ridhita Sriji Maharaj, died, they said.
The victim, who was part of a group of nuns which was on its way to Padra on foot, was left behind due to fatigue and while crossing the bridge she jumped into the river, police said.
She had recently undergone a surgery for kidney stone and was not keeping well, they added.
The dead body was recovered and handed over to the members of the Jain community at their request without postmortem, police said.