The two contracts are estimated to be worth INR 20.79bn ($469.83m).
The Punatsangchhu Hydro electric project is being developed jointly by the Bhutanese government and the Indian government.
The first contract worth INR12.24bn ($276.61m) includes construction of diversion tunnel, dam intake and de-silting arrangement including hydro-mechanical works and a highway tunnel.
Under the second contract worth INR8.55bn ($193.22m), the company will build a head race tunnel from surge shaft end, surge shaft, butterfly valve, chamber, pressure shafts, power house and tailrace tunnel including hydro-mechanical works.
