My Airport 6.1 can't manage my base station. I need to use AirPort Utility 5.6 but i can't find the right. I've download several but it always give me the same message: Airport uti....can't be installed... The version of OS X on this version is not compat

Use AirPort Utility 5.6 which contains the features you need. It is compatible with Lion as well as Mountain Lion, however, the installer app will refuse to install it on Mountain Lion.

This dilemma is easily solved though. You simply need to extract the app from the installer package using a package extractor like Pacifist.

Download Pacifist here: http://www.charlessoft.com/

Download AirPort Utility 5.6 here: http://support.apple.com/kb/DL1482

If you happen to have an archived copy of the AU 5.6 app somewhere, such as a Time Machine backup or equivalent, you can simply restore it or drag the app to your Mountain Lion system's Utilities folder. It will run without complaint. It is only the package installer that is the problem.

Mountain Lion will not allow you to delete its existing version of AirPort Utility. Just ignore it. It and the older version (which will bear the unique name "AirPort Utility 5.6") can peacefully coexist.

Note: For those with Leopard or Snow Leopard systems you need AirPort Utility 5.6.1 (this is confusing - a later AirPort Utility version for an earlier OS X version - but it is correct).

Download AirPort Utility 5.6.1 here: http://support.apple.com/kb/DL1536

Looks like this is no longer an option for Mavericks users.. Airport Utility won't run on Mavericks. (Error is: "You can't use this version of the application "Airport Utility 5.6" with this version of OS X.")