Add radio button on theme at the select of the theme the same theme should be activated after generation of new site in multi site

Please paste the below code in the function.php file to activate the theme from front end

/**
* Add custom field to registration form
*/
add_action( ‘signup_blogform’, ‘aoc_show_addtional_fields’ );
add_action( ‘user_register’, ‘aoc_register_extra_fields’ );

function aoc_show_addtional_fields()
{
$themes = wp_get_themes();
echo ‘Choose template for your site’;
foreach ($themes as $theme){
echo ‘get_screenshot().'” width=”240″/>’;
echo $theme->name . ‘ template.'” name=”template” />’;
}
echo ”;
}

function aoc_register_extra_fields ( $user_id, $password = “”, $meta = array() ) {
update_user_meta( $user_id, ‘template’, $_POST[‘template’] );
}

// The value submitted in our custom input field needs to be added to meta array as the user might not be created yet.
add_filter(‘add_signup_meta’, ‘aoc_append_extra_field_as_meta’);
function aoc_append_extra_field_as_meta($meta)
{
if(isset($_REQUEST[‘template’])) {
$meta[‘template’] = $_REQUEST[‘template’];
}
return $meta;
}

// Once the new site added by registered user is created and activated by user after email verification, update the template selected by user in database.
add_action(‘wpmu_new_blog’, ‘aoc_extra_field’, 10, 6);
function aoc_extra_field($blog_id, $user_id, $domain, $path, $site_id, $meta)
{
update_blog_option($blog_id, ‘template’, $meta[‘template’]);
update_blog_option($blog_id, ‘stylesheet’, $meta[‘template’]);
}