Oil and Natural Gas Corp. Ltd (ONGC) is unperturbed by the sanctions imposed by the U.S. and the European Union (EU) on Russia, a country in which India’s biggest oil and gas explorer owns stakes in significant hydrocarbon assets. The EU and the U.S. have imposed sanctions on Russia and are threatening to expand their ambit after Russia absorbed the Ukrainian region of Crimea following a referendum that approved the secession. “If it is the UN sanctions then we are bothered. If one country or a group of countries imposes sanctions then we may not give much cognizance to that,” said Dinesh K. Sarraf, chairman and managing director of ONGC.