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

• RenderMan for Houdini 24.2 supports: 18.0.597, 18.5.633, 18.5.672, 18.5.696, and 19.0.383
• RenderMan for Houdini 24.3 supports: 18.0.597, 18.5.672, 18.5.696, 18.5.759, 19.0.383, and 19.0.455
• RenderMan for Houdini 24.4 supports: 18.0.597, 18.5.672, 18.5.696, 18.5.759, 19.0.455, 19.0.561, and 19.0.589

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.