Salim Ansari, one of 29 men trapped in the mine since Friday, was rushed to hospital unconscious.
"He was found in level one where the water has almost receded," Ramanuj Prasad, a spokesman of Bharat Coking Coal Ltd, told Reuters from the eastern town of Dhanbad.
Company officials had said that the chances of finding anyone alive in the submerged mine were remote after naval divers failed to make any contact with the trapped men. The divers found the body of one of the miners early in the rescue effort.
At least 100 miners were working underground when the disaster struck on Friday. Sixty-five miners were rescued immediately. Later the mining company said there were 30 men trapped below.
Prasad said level one of the mine would be completely "de-watered" by afternoon.
"Rescuers will then go inside to locate and recover," he said.
Security has been tightened around the mine after relatives of the miners protested against the slow pace of the rescue. One newspaper quoted a relative as saying that the men should be brought out "dead or alive."