shell_exec not taking Urdu word

Question

I have a PHP code in which shell_exec command takes a word and make it as an argument to the jar file (that simply displays the argument yet). But when I echo the result for any Urdu word it displays '?????'

My jar works absolutely fine with English word, but not for any Urdu word.

My code is

   <?php
   $q="علی";
   $out="/path/to/jar/myJar.jar  $q";
   $out2=shell_exec($out);
   echo $out2;
   ?>