W3C is hosted by four organizations on three continents: the Massachusetts Institute of Technology (MIT) in the United States, the European Research Consortium for Informatics and Mathematics (ERCIM) in Europe, the Keio University in Japan and Beihang University in China. You can find the contact persons at these hosts by consulting the general contact page. W3C has also developed a program to partner with regional organizations to host W3C Offices, which act as local points of contact, and which make sure that W3C and its specifications are known in their region. The mission of a W3C Office can be summarized as follows:
To promote adoption of W3C recommendations among developers, application builders, and standards setters, and to encourage inclusion of stakeholder organizations in the creation of future recommendations by joining W3C.
A separate page gives more details on the role of W3C Offices. If your institution is interested in possibly hosting an Office, you should also read the conditions for hosting an Office.