50 Rupees Oil and Natural Gas Corporation

The Oil and Natural Gas Corporation was founded in 1956 as a commission under the Indian Ministry of Petroleum, converting to a full government corporation in 1961. By 2006, ONGC had become one of Asia's largest exploration and production companies, accounting for roughly 70 percent of India's domestic crude output. This commemorative was issued to mark the corporation's fifty-year anniversary.

The .500 fine silver specification was standard practice for Indian commemoratives of this period — a cost-control decision that kept official issues affordable while maintaining a silver content high enough to justify the metal designation.