This document provides a summary of the history and operations of Oil and Natural Gas Corporation Limited (ONGC), India's largest oil and gas company. It discusses how ONGC was established in 1956 by the government of India to develop the country's oil and natural gas resources. It outlines ONGC's key discoveries and expansions from the 1960s onward, including major offshore finds. The document also provides background on ONGC's operations, locations, employees and facilities.