At long last, Windows Server 2016 support is coming. The currently posted version of Directory Search v3.0 is already ready for Windows Server 2016.
Directory Update v3.0, Directory Manager v3.0, and Directory Password v3.0 are out of beta testing and in production at some customers. Contact support if you want to be an early adopter. Limited documentation is available. We do have an XML file converter for the DirectorySettings.XML and AppSettings.XML if you are running current versions.
Prerequisites for W2K16 are the same as W2K12 R2. And, as always, perform full Microsoft updates on any version of Windows to get all operating system and .NET Framework updates that are available.