Your question is not clear. Please explain what are you looking for.
I can tell you that we're using it in various places.
As far as it being supported, that depends on what exactly you're using it for. But for simple database directory output, it works. For database files (eg RMAN) support is going to be more problematic.
Oracle metalink has an update on this as below:
Mounting a CIFS filesystem from an Exadata node fails (Doc ID 1368880.1)
CIFS filesystem mount appears to work in Exadata db computing node.
Install the samba-client package from installation media or from ULN before run mount command. You are doing right to reach support to get more details on any issues/document.