If you want to display the attached image gallery, from another post, you can use:
[gallery id="123"]
where the custom id attribute is the post ID.
If you want limit the number of items in a gallery, there seems to be a plugin available on wordpress.org called Limit parameter for gallery shortcode (no affiliation). It uses the pre_get_posts filter to change the posts_per_page and offset attributes of the get_posts() or get_children() calls in the gallery shortcode callback.
Example:
[gallery id="4" limit="3" offset="1"]