What are United nations recognized universities?

The United Nations doesn't "recognize" universities in the sense of having an official list of approved institutions. There's no UN accreditation process for universities. The UN collaborates with many universities around the world on various projects and initiatives, but this collaboration doesn't imply any formal UN endorsement or recognition of the university's quality or legitimacy.

Universities gain recognition and legitimacy through regional and national accreditation bodies within their respective countries. These bodies are responsible for setting standards and evaluating the quality of education provided by universities. Therefore, whether a university is considered reputable and trustworthy depends on its accreditation status within its own country and region, not on any UN designation.