Auto login after register user in wordpress and redirect to a home page.

snippet.php

<?php
// Download this snippet as a plugin and more at: https://wordbits.io/snippet/auto-login-after-registration/
// Created by: Ravi Patel
?>

<?php
function auto_login_new_user( $user_id ) {
    wp_set_current_user($user_id);
    wp_set_auth_cookie($user_id);
    wp_redirect( home_url() );
}