When using 12c database, you may have internal container databases. In order to manage them i.e. tablespaces etc, you need to configure each container database’s em console. You can do this via logging into the container database as sysdba i.e.
sqlplus sys/password@instance as sysdba
Then issue :-
exec dbms_xdb_config.sethttpsport(5501);
This will configure the container database to deploy a EM Console to port 5501. You will then have the ability to launch a browser session to http:<host>:5501/em/console :-
You will then have the ability to manager the container databases tablespaces etc :-
