Oracle 11g and 12 is supported by CCC 2.9.4. (and RAC, with special configuration of JDBC URL)
Exadata can be configured to use RAC, it is, then you have to configure the CAPMAN database to only talk to one of the RAC nodes. (Cannot be in failover nor load balancing mode.)
If Exadata is 11g compatible and without RAC it should work just fine.
If it is setup for 12 then you need to follow the special instructions in the install guide for setting up the Userid for Oracle 12.
Because Oracle says it will support any Oracle DB product it should work fine,
David