According to the subversion repo, the latest revision for Indy 10 is r4910. The ZIP file that you link to is named Indy10_4910.zip. So that is as up-to-date as you can be.
The way to check something like this is to look at the source control repo yourself. The Indy website has a source control repo gateway page here: http://www.indyproject.org/sockets/Download/svn.EN.aspx
Update: If what @mjn says is true then the ZIP file may be out of date. I would always use svn to pull off the latest version.