Take muri express from ambala up to renukut , then hire taxi or up state buses run in every half hour to singrauli , renukut to singrauli is 60 km.
or take kalka mail from chandgarh/ambala and deboard at allahabad , then take triveni express till singrauli , on alternate days it runs to shaktinagar , no worries shaktinagar is 20 km from singrauli.