Questions about the AUCTeX package for editing (La)TeX code/documents in Emacs.
The AUCTeX website is at https://www.gnu.org/software/auctex/.
Tex.SE also an auctex tag; the one here on SO is probably more appropriate if you expect the answer to your question to involve programming in lisp, whereas the one on tex.SE might be more appropriate if you expect it to involve tricky option settings, or if you would like to be told you should be using TeX package foo
rather than trying to get your editor to deal with the verbosity of bar
. (No biggie either way, though.)