Start by browsing the relevant documentation to see if you can find an answer to your question.
You can review questions and answers on the Renjin tag on StackOverflow.com.
For general questions, updates, and discussing, join our mailing list on Google Groups.
If Renjin does not produce an expected result, you can open an issue on our GitHub project.
We are trying to do monthly working sessions on Renjin to which everyone is welcome: