The Sitecore Commerce Server 11.1 BizTalk Adapter has been tested with and supports Biztalk Server 2013 R2. However, the following error message is shown when the standalone Biztalk adapter installer (e.g. BTSAdapters-11.1.79.0.exe) is used on a machine with BizTalk Server 2013 R2:
You must have Microsoft BizTalk Server 2009 or 2010 installed in order to install Commerce 11 - BizTalk Servers Adapters
The error is caused by an incorrect dependency checking logic inside the standalone BizTalk adapter installer.
Note: The BizTalk adapter component is also included in the main Commerce Server installer (e.g. CommerceServer-11.1.79.0.exe), which can be installed on a machine with BizTalk Server 2013 R2. The BizTalk Adapter installers inside Sitecore Commerce Server 11.2 and above do not have this problem.
To resolve the issue, use the BTSAdapters-11.1.93.0.exe installer.