PHP rename function does not working

You need to get your real path, for me real path /Applications/MAMP/htdocs/phptest but you can define ABSPATH like define('ABSPATH', dirname(__FILE__).'/');

Complete code:

 error_reporting(1);
 error_reporting('On');

define('ABSPATH', dirname(__FILE__).'/');

include 'includes/config.php';    // database configuration file

$file_name = "images800466507.jpg";
$currentPath = ABSPATH.'/TempImages/'.$file_name;    // ( file permission : 777 )
$newPath = ABSPATH.'/ImagesNew/'.$file_name;     // ( file permission : 755 )
if( rename($currentPath ,$newPath ) )
   echo 'done';
else
   echo 'not done';

I tested and it worked for me.