Alchohol??? Nero??? harlo, this is Apple section lar
use Toast will do.

try mount it with toast or disk utility.

To create an ISO image in OS X, use Disk Utility to burn a new image choosing "CD/DVD Master" as the Image Format. That creates an image with the cdr extension. Just rename the cdr file extension to iso and there you have it!

If you already have a DMG and want to convert it to an ISO, you can use hdiutil to do so:

hdiutil convert discimage.dmg -format UDTO -o output.iso

it's a Terminal command. the last line of my post is the command to input.