We are a user of both WebLogic and OPA. We are planning to do an upgrade next year from WebLogic 10.3.0 --> 12.1.1.
I have still not find any documentation what version of OPA we should use together with WebLogic 121.1. Please let me know.
OPA 10.4.0 and later are certified for WebLogic 12c. See the system requirements presentations here: http://www.oracle.com/technetwork/apps-tech/policy-automation/overview/index.html
For example http://www.oracle.com/technetwork/apps-tech/policy-automation/documentation/opasystemrequirements10-4-1-1713415.pdf