When you transclude a page (that is, automate the display of a page's content on another page), all its tags (like ((TOCRight))) go with it, which will be implemented on the host page. Just add the following code if you want to add a right-aligned TOC to a page, but do not want it to be displayed on "derivative" pages:

<noinclude> ((TOCright)) </noinclude>

For a more detailed explanation, see Help:Wiki markup#Templates and transcluding pages.