There is no reason to assume that consumers would look at
/rss.xml when they are looking for a feed. Feeds don’t have a reserved filename/location.
You would typically link your feeds from relevant pages, by providing
link elements with the
alternate link type and a
type value of
application/atom+xml in case of Atom feeds).
If you are using a
link element, you might want to add a visible link in addition.
If you offer multiple feeds, note that the order matters.
(Which consumers are interested in your feeds is a different question, of course. If a consumer is interested, but not using the standardized HTML links, they would hopefully document an alternative way.)