Attach a particular profile2 form to user registration form
try this,

$user_register_form = drupal_get_form('user_register_form');
$form_state['profiles'] = array(
'CUSTOM_PROFILE_TYPE_NAME' =&gt; profile2_get_types('CUSTOM_PROFILE_TYPE_NAME')
);
profile2_attach_form($user_register_form, $form_state);
print(drupal_render($user_register_form));