5.1.4.4 Using an Existing Oracle Software Owner User

If the user you have decided to use as an Oracle Home user exists, then you can use this user as the Oracle Home user for a different installation.

Oracle does not support changing the ownership of an existing Oracle Database home from one Oracle Home user to a different user.

During the software installation, specify the existing user for the Oracle Home user.
Oracle Universal Installer (OUI) creates the appropriate group memberships.