Within articles, this template is meant to be placed at the bottom of the article in the Xem thêm section. If there is no Xem thêm section, you can put it in the Liên kết ngoài section instead; there is no need to create a new section just to house this template. If there is no Liên kết ngoài section either, just put it below the article text in the place that seems most appropriate.

There are no particular rules about the placement of portals on other kinds of page.