You should be able to run the modpack installer .exe on a Mac through CrossOver software (fancy commercial wine port). Just make sure you point the installer to the correct path for the game when asked.
When I first started playing WoT I played it on OSX exclusively for the first few months, but the performance hit was too big for me so I installed Windows on a BootCamp partition and gained almost 50% FPS. I would wholeheartedly advise you to do the same.
If you rather decide to continue playing on Mac OS, just make sure to install all the fonts necessary. I remember having some problems with missing characters after installing modpacks. But it was long time ago - after my first windows battle, I deleted the game on OSX.