As stated here How To Retrieve An Image Attachment's Alt Text?
"Image's 'alt' text is stored as a string in wp_postmeta with the meta_key of '_wp_attachment_image_alt'"
I am using below code to print alt tag of attached image...
<? get_post_meta($post->ID, '_wp_attachment_image_alt', true); ?>
But it is not working.
<?php get_image_tag( $id, $alt, $title, $align, $size ); ?>