Download of Better Rename 11 11.61 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The application lies within System Tools, more precisely File Managers. We recommend checking the downloaded files with any free antivirus. This software for Mac OS X is a product of Frank Reiff.
From the developer:
Better Rename 11 is a complete renaming solution for your files. It supports complex renaming tasks without sacrificing ease and speed of use. You simply drag the files you want to rename straight from the Finder into the large preview table or the application icon, or you can use the provided Finder context menu and hot key.
You may want to check out more software for Mac, such as MPV's iPhoto '11 101 - Core iPhoto '11, Files Renamer or File Renamer Lite, which might be related to Better Rename 11.