To Stream content from a Geo-Restricted site, first of all, you will need to know which country the content is geo-restricted to. For example, if you want to watch The Office (US), it is currently only available on Netflix Canada, so this is what you should do:
It is as simple as that for most of the major streaming sites, including geo-restricted sites. Sometimes you will need to restart the streaming app or close and re-open the streaming website's tab in order to fully reload it.