If you haven't committed the changes yet, you can do as follows (on that pic I "accidentally" deleted conf/map folder with all contents):
Right click on your repository folder or the folder you accidentally deleted files from (whichever you like). Then hover the mouse over TortoiseGit and select Revert... on the new menu.
A new window will appear. This will let you select any of the files you deleted or modified for reverting the changes (on all the repository or just in that folder if you opted for selecting that folder). Watch out since if you revert a modified file, you won't be able to retrieve your former changes. Select what you want to revert, then click OK
A new window will appear, which will revert all selected files for you. Wait for it to finish, then click OK an now you're done!
Hope this works!
P.S.: If you don't know if you have committed it or that word doesn't seem familiar to you, then chances are you haven't done it since commits are almost always done on purpose
Sorry for using the Spanish UI, but it shouldn't be much of a problem here since I use English TortoiseGit.