Its not available in tabcmd
you need to open the tableau server
go to the tableau server --> bin location
then write tabadmin stop
Hope this helps
I am working on the Tableau Server. Our Tableau Desktop is on the server.
It appears that maybe you are in the desktop directory instead of the server directory, unless you customized where you have the install for server.
try navigating to c:\program files\tableau\tableau server\10.4\bin which I think is the default install location, and see if this lets you do the tabadmin here.