Rescue crews are considering drilling an escape shaft to reach the 41 miners in the collapsed tunnel.
In the northern Himalayan state of Uttarakhand, time is running out.
On Friday, the rescue crews had to stop the drilling attempts due to fear of new collapses.
Soil, concrete and construction waste have been removed from the top and mouth of the collapsed, under-construction tunnel.
Rescue efforts are being slowed down by faults in the lifting equipment. Indian Air Force helicopters have transported new equipment to the accident site twice.
The minister of transport who visited the tunnel site on Sunday Nitin Gadkari said that the men could be reached on Tuesday if the drilling rig could be fixed.
Attempts have been made to push a 90-centimeter-wide steel pipe into the tunnel, through which the men could be brought to the surface.
One option is to drill a new, more than one hundred meter deep rescue pit.
Food and medicine through the pipeline
Relatives of those trapped have been talking underground using walkie-talkies. The conditions in the tunnel are characterized as very harsh. Despair is said to be growing day by day.
Food, water, oxygen equipment and medicine have been delivered to the men in a 15-centimeter-wide rescue tube.
Foreign accident investigators and mine rescue professionals have been invited to the place.
Mining accidents are common in Uttarakhand, as the region is prone to landslides.
A shrine of the local Hindu god Boukhnag has been built at the mouth of the tunnel to give faith in the success of the rescue work. The original temple has been moved elsewhere due to construction projects.
AFP