The query show user list orderby count published posts in last month

I presume you want to get the users who registered during the last month based on their post count.

Use the following code:

$args = array(
    'orderby'    => 'post_count',  // Gets the users based on the no. of posts they have made.
    'order'      => 'DESC',
    'role'       => 'Subscriber',  // Gets the users with this role.
    'number'     => 4,  // Total no. of users that the query outputs.
    'date_query' => array(
        array(
            'after'     => '1 month ago',  // Gets the users registered during the last month.
            'inclusive' => true,
        )
    ),
);

$users = new WP_User_Query($args);

foreach( $users as $user ) {
    echo $user->display_name . '<br>'; // Outputs the user's display name on a new line.
}