The main function of NNPC (Nigerian National Petroleum Corporation) is to oversee the development of the oil sector in Nigeria. This includes managing the exploration, production, and distribution of petroleum products, as well as ensuring that the country's oil reserves are used in a sustainable and responsible manner. NNPC also works to promote investment in the oil sector, both domestically and internationally, and to maintain good relationships with other countries that are involved in the production and distribution of petroleum products. In addition, NNPC plays a key role in regulating the oil industry in Nigeria, ensuring that companies operating in the sector comply with all relevant laws and regulations.