You could do it in this way.
echo do_shortcode('[mu-events months="11" startmonth="today" orderby="time" orderas="ASC" sites="' . get_current_site() . '"]');
You could do it in this way.
echo do_shortcode('[mu-events months="11" startmonth="today" orderby="time" orderas="ASC" sites="' . get_current_site() . '"]');