You have to place the ojdbc6.jar in the server/.../lib directory
and do not place different oracle jar here or bundle different to applications.
I have places in this location but still not working,
server\default\lib is okay. Make sure, that you use the default-directory. If not, than put the libs into jboss/lib to have access for all deploy-directories. To avoid conflicts, dont package the drivers into your war/ear.
You use EAP supported server.
Here it may possible that the 'production' configuration is startet if nothing is specified with 'run.sh -c' ...
You might check this within the start messages.
Or use -c default ...