YOu cannot directly import Mac Thunderbird mail folders in windows outlook. Firstly convert the thunderbird files to pst format using Thunderbird to PST Converter and then follow these steps to import the converted pst file into windows outlook 2013:
Follow these steps to restore, or import, your data into Outlook:
Click the File tab.
In the Open category, click Import.
In the Import and Export Wizard, click Import from another program or file, and then click Next.
Click Outlook Data File (.pst), and then click Next.
Type the path and the name of the .pst file that you want to import, or click Browse to choose the file to import.
Note Under Options, it is recommended that you click Do not import duplicates, unless you want the imported information to replace or duplicate items that are already in Outlook.
Select the folder that you want to import. To import everything in the .pst file, select the top of the hierarchy.
Note The top folder (usually Personal Folders, Outlook Data File or your email address) is selected automatically. Include subfolders is selected by default. All folders under the folder selected will be imported