I think that the question may refer to whether the PageRank is fake, though I don't understand why someone would want to check their own site, as surely they would know already if it was.
Anyway, apparently some sites use a redirect from a site with a high PR to another site, so that the second site assumes the PR value of the original. There are fake Pagerank checkers freely available from a Google search that claim they can check whether a redirect is in place, though I haven't had occasion to use any of them and don't know if they are effective.