<?php
            session_start();
            $conn=oci_connect('localhost','pass','IP....');
            $stid=oci_parse($conn,"select arabic_name from arabic_names_table");
            oci_execute($stid);
            if($row-oci_fetch_array($stid,OCI_ASSOC+OCI_RETURNS_NULLS))
                {
                 $name_ar=$row['arabic_name'];
                 }
           ?>

$win1256 = iconv('windows-1256', 'utf-8', $my_string); //$my_string -> windows-1256
echo $win1256; // Results the utf-8 format .