Hi,

Have you tried to use AutoCAD 2013 download page which I provided in my previous post?
Here is the direct link:

http://download.autodesk.com/us/support/files/autocad_2013_mac_full/AutoCAD_2013_English_Mac_OSX_R2....

AutoCAD for Mac 2013 System Requirements

• Apple® Mac OS® X v10.8.0 or later (Mountain Lion), OS X v10.7.2 or later (Lion), or OS X v10.6.8 or later (Snow Leopard) with 64-bit Intel processor

Maxim