<?php

$listSort[] = array('email' => 'a@b.c', 'name' => 'x', 'umur' => 21);
$listSort[] = array('email' => 'a2@b.c', 'name' => 'y', 'umur' => 11);
$listSort[] = array('email' => 'a3@b.c', 'name' => 'z', 'umur' => 33);

foreach ($listSort as $key => $row) {
    $name2[$key] = $row['name'];
    $umur2[$key] = $row['umur'];
}

array_multisort($umur2, SORT_DESC, $name2, SORT_ASC, $listSort);

echo '<pre>';
echo print_r($listSort);
echo '</pre>';