General Restrictions for Using Earlier Oracle Database Releases

You can use Oracle Database 21c, 19c, 18c, and Oracle Database 12c release 2 with Oracle Grid Infrastructure 21c.

Do not use the versions of srvctl, lsnrctl, or other Oracle Grid infrastructure home tools to administer earlier version databases. Only administer earlier Oracle Database releases using the tools in the earlier Oracle Database homes. To ensure that the versions of the tools you are using are the correct tools for those earlier release databases, run the tools from the Oracle home of the database or object you are managing.