RenderMan for Houdini (RfH) only provides support for the following production Houdini versions:

• RenderMan for Houdini 25.0 supports: 19.5.569, 19.0.720, 18.5.696
• RenderMan for Houdini 25.1 supports: 19.5.605, 19.5.569, 19.0.720, 18.5.696

Other important information:

• RenderMan for Houdini will not operate with a mismatched python version. Be careful to install the same python version for Houdini and RfH. 
• Rendering with RenderMan will not operate on Houdini Apprentice editions, see Side FX's website for options that allow Third Party Rendering
• RenderMan for Houdini for 19.0 requires macOS 10.14 and higher or CentOS 7.7 and higher.