Oracle 12.2c provider generates errors during the installation process. As a result RED-IM fails to recognize that the provider was installed. This is indicated in the Data Store Config dialog errors during the install process.
Use the Oracle 184.108.40.206 32-bit installer instead, there should be no errors during the installation process and, Then the correct Oracle provider is listed as an option in the Data Store config dialog. You should now able to successfully connect to the target Oracle backend and successfully manage Oracle accounts.
The Oracle 12.2c provider AS RELEASED does not seem to install properly on Windows Server, so you need to install the updated Oracle provider "Oracle 220.127.116.11" 32-bit installer.
Use the OLE DB provider from the dropdown list with the "Provider=OraOLEDB.Oracle.1" as part of the connection string. This is the one that invokes the ODP.NET driver.
You can download here: http://www.oracle.com/technetwork/topics/dotnet/utilsoft-086879.html (see section ODAC 12c Release 4 and Oracle Developer Tools for Visual Studio (18.104.22.168.4))