I got an alternative :
This will not just hiding but disabling also
function disable_comments() {
$post_types = get_post_types();
foreach ($post_types as $post_type) {
if(post_type_supports($post_type,'comments')) {
remove_post_type_support($post_type,'comments');
remove_post_type_support($post_type,'trackbacks');
}
}
}
add_action('admin_init','disable_comments');