From Stamps of the World
Delhi, also known as the National Capital Territory of India is a metropolitan region in India. It has a population of nearly 22.2 million residents as of 2011, and is the largest city in India by land area. The NCT and its urban region have been given the special status of National Capital Region (NCR) under the Constitution of India's 69th amendment act of 1991.
The Current GPO is found at Lothian Road at Kashmere Gate, in a more modern building. Opposite the Delhi Railway Station.