Choose a New Location for Oracle Home when Upgrading
You cannot install the new software into the same location for Oracle home as your current release.
You must choose a location for Oracle home for the new release of Oracle Database that is separate from the Oracle home of your current release.
Using separate installation locations enables you to keep your existing Oracle software installed along with the new Oracle software. This method enables you to test the upgrade process on a test database before replacing your production environment entirely.