Coinco is a Chilean commune and town in Cachapoal Province, O'Higgins Region. According to the 2012 census, the commune population wa…Coinco is a Chilean commune and town in Cachapoal Province, O'Higgins Region. According to the 2012 census, the commune population was 6,709 and has an area of 98.2 km. According to the 2002 census of the National Statistics Institute, Coinco has 6,385 inhabitants. Of these, 4,102 lived in urban areas and 2,283 in rural areas. The population grew by 9.7% between the 1992 and 2002 censuses.