765kV GIS Extension Substation Package SS158 for (a) Extn. of 765/400kV Sasaram (POWERGRID) S/S associated with ERES-51: Diameter completion at Sasaram (POWERGRID) S/s and (b) Extn. of 220kV Nalagarh (POWERGRID) S/S associated with Implementation of 2 nos. 220kV line bays (GIS) at 400/220kV Nalagarh (PG) S/s for the termination of 220kV D/c line from 220/132kV Kunihar S/s to Nalagarh S/s/CC/NT/W-GIS/DOM/A02/26/13152/28677