Unfortunately, TurboTax Download version is for Windows only. However, you can request a refund for your TurboTax product(s) within 60 days of the original purchase date by clicking on the following link: How do I get a refund for a TurboTax product? and fill out the form.
Another option is to use TurboTax Online. It works very well and and can be used with Mac and Windows.