is it possible to call 'CActiveForm::error'?

Is it possible to call like the following directly.

<?php echo CActiveForm::error($PolicyFamilyDetails,'first_name');?>

You mean without creating a CActiveForm widget?

You could use CHtml::error().

But when I use CHtml, i couldn’t able to validate using the clientValidation of CActiveForm

If you’re using an instance of CActiveForm, just use $form->error($model, $attr);