How to Retrieve data of Gallery Shortcode and display it above a post

I am also seeking the same solution. I am going to create a gallery filter function – an extension to this. Do you want to collaborate?

function get_post_gallery( $post = 0, $html = true ) {
$galleries = get_post_galleries( $post, $html );
$gallery = reset( $galleries );

/**
 * Filter the first-found post gallery.
 *
 * @since 3.6.0
 *
 * @param array       $gallery   The first-found post gallery.
 * @param int|WP_Post $post      Post ID or object.
 * @param array       $galleries Associative array of all found post galleries.
 */
return apply_filters( 'get_post_gallery', $gallery, $post, $galleries );
}