If you deleted a few files and you have not made a commit yet, Revert will work just fine. Selecting TortoiseGit -> Revert… will display a window for you to select the files you want restored. Deleted files will show in red.
If you already committed the delete, then you can Reset to a commit before you deleted the files. Be warned that if you use reset, you will no longer see in your log the commit(s) after the commit you reset to.
If you want to preserve in your log the commit that deleted the files, you can Checkout the commit before the delete into a new branch, copy the restored files into a separate folder, switch back to your original branch, then add the files back to your original branch.