By default, Tableau Server wants to listen on port 80. Does OBIEE or any of it's components also listen on 80? If so, you'll need to change Tableau Server's configuration.
In general, Tableau likes it's own server, just like OBIEE does. However if you're sure they won't steal resources from each other so that neither perform well, you can probably get away with this...not in production, though!
Thanks Russell. I was able to co-host and it works as expected. Let see what happens in the long run.