I haven't tested it because I don't have a mac, but Wine allows windows programs to run on a mac. Supposedly some of their users have been able to have some success with it, so you might want to read up on it. If that doesn't work, use bootcamp and install a copy of windows 7 or 8.1 on it.
In my tries I've found that Wine on Mac isn't emulating certain calls to DirectPlay API's, making it impossible for Freelancer to generate and validate account ID's, making impossible to get pass "Here's your account ID!" dialog.
I tried on the wife's mac, and ran the gauntlet of wine and bootcamp, only to find that it will let you play singleplayer....maybe. I gave up and bought a new pc.