If you would like to push Office Chat to your users via a Group Policy download the MSI installer from the link below.
Please ensure the following prerequisites that are required by Office Chat for Windows installer
Office Chat MSI Installer
1Microsoft .NET Framework 4.5.1 Client Profile or above is installed on the target machines
2Microsoft Visual studio tools for Office Runtime 2010 is installed on the target machines
3Microsoft Visual C++ 2012 Redistributable is installed on the target machines
4The installer is required to be run as an administrator since it installs to the users Program Files directory.