Form fields override

Hello and good afternoon,
I'm trying to override the function "echo $this->loadTemplate('login', array('fields' => $fields))" to change the look of form fields in registration form.
Could I know where "login" template is located? Becaude I've tried to override the default Joomla "renderfield.php" located in "layouts/joomla/form" but without success.

Thanks,
Kind regards

I'm sorry, I've disturbed you for nothing.
I report here the solution is can be useful for other people...
I've just found the solution myself, I have to override "com_osmembership/views/register/tmpl/default_form.php", that's it.

Kind regards