In order to select and download the correct and latest release of OPatch, you have to know the current Oracle Universal Installer (OUI) version first.
Check All Version of Opatch
To check OUI version, we can use opatch version -all to list all related versions including OUI.
[oracle@ora19c ~]$ $ORACLE_HOME/OPatch/opatch version -all
Oracle Interim Patch Installer version 12.2.0.1.23
Copyright (c) 2021, Oracle Corporation. All rights reserved.
Oracle Home : /u01/app/oracle/product/19.3.0/dbhome_1
Central Inventory : /u01/app/oraInventory
from : /u01/app/oracle/product/19.3.0/dbhome_1/oraInst.loc
OPatch version : 12.2.0.1.23
OUI version : 12.2.0.7.0
Log file location : /u01/app/oracle/product/19.3.0/dbhome_1/cfgtoollogs/opatch/opatch2020-11-02_05-25-05AM_1.log
OPatch version for all Oracle Homes registered in Central Inventory:
Location Version
/u01/app/oracle/product/19.3.0/dbhome_1 12.2.0.1.23
The release number of OUI is 12.2.0.7.0 currently, it's pretty new for release 19.8 to patch new Database Release Update (DBRU).
List All Inventory
Listing all inventory by opatch lsinventory can also get the OUI version.
[oracle@ora12c ~]$ $ORACLE_HOME/OPatch/opatch lsinventory
Oracle Interim Patch Installer version 12.2.0.1.21
Copyright (c) 2020, Oracle Corporation. All rights reserved.
Oracle Home : /u01/app/oracle/product/12.1.0.2/db_1
Central Inventory : /u01/app/oraInventory
from : /u01/app/oracle/product/12.1.0.2/db_1/oraInst.loc
OPatch version : 12.2.0.1.21
OUI version : 12.1.0.2.0
Now we know the release number of OUI is 12.1.0.2.0.