For a stable experience on El Capitan (10.11), the best versions to target are .
Visit the MAMP Downloads Page and look for the "Version History" or "Older Versions" link at the bottom. mamp download for mac 10.11
If the official site lacks a specific old build, sites like MacUpdate or Uptodown host version histories. Installation Steps for El Capitan MAMP not starting Apache server on El Capitan 10.11.1 For a stable experience on El Capitan (10