As far as I understood, you have an asp.net application using jquery. But what code do you want to access the folder properties? The c#/VB or jquery?
If you are looking for a javascript code, this should do the job:
var fso = new ActiveXObject("Scripting.FileSystemObject");
var folderPath = "c:\\HERE_COMES_YOUR_FOLDER_PATH";
if (!fso.FolderExists(folderPath)) {
alert('Folder does not exist');
return false;
}
else {
alert('Folder exists');
return true;
}