Pykara Hydroelectric Plant was built in ______.

The correct option is 1931.

The Pykara Hydroelectric Plant is a historic run-of-the-river power project located in the Nilgiris district of Tamil Nadu, India. The plant is built on the Pykara River, which is sacred to the local Toda people and is known for its dramatic drops and waterfalls.
Under the leadership of the Madras Government and visionary planning, construction on the Pykara project began in the late 1920s. The civil works and primary construction of the power house and water conduits were completed in the year 1931, leading to the official commissioning and generation of electricity starting in 1932. Thus, the plant was built in 1931.