Migration TFS to RTC
2 answers
If you want the code migrated then it's a "double bounce" - you first need to export from TFS to Subversion with history and then import from Subversion.
If you do a Google search you'll find several articles talking about how to export TFS to SVN, see some of these:
and also this earlier Forum reply
and from there it's 'pretty' easy to import an SVN archive into RTC using the RTC Eclipse client: