Is this Extension Pack Version compatible with Mari 5 or Mari 4 ?


No. 


Mari Extension Pack 6 requires at minimum Mari 6.0 to run. It is also compatible with Mari 7, via a separate Installer.



However with your purchase of Mari Extension Pack 6 you also gain access to previous versions.


To use Mari Extension Pack with Mari 4.x or Mari 5.x use Mari Extension Pack 5R9 which is available with your purchase