The minimum entrance requirements for admission to higher education in Norway can be found in the GSU List (hkdir.no). This list states the basic requirements for admission to higher education in Norway. The list consists of both education requirements and language proficiency requirements in English and Norwegian.
The Norwegian Upper Secondary School Leaving Certificate is based on 13 years of schooling. This is longer than in many other countries and you should therefore check if there are additional requirements for your country.