I am trying to plan a migration of a server with Tortoise 1.6.21511, which is running on a W2008R2 server. I want to install the most up to date version or Tortoise - 1.6.21511 - and I would like to know the associated server version.
The most up to date version of TortoiseSVN is 1.14.0 and it is compatible with Windows 2008 R2. You can download it from the official TortoiseSVN website. The associated server version will depend on the version of SVN installed on the server.