You can use the SaveAs() to save the uploaded files to the desired target folder. For example you can check some conditions like file extension and based on that set the target path.
If you set the TargetFolder or TargetPhysicalFolder property and
then use the server-side API to manipulate the uploaded files, you may end up with two copies of the uploaded files.
Be aware that any valid files will already be saved to the target folder.
Please have a look into the following code that illustrates how to save uploaded files to a location of your choice.