In Futurama it is said a Robot equivalent of DNA

Ribonucleic acid, or RNA, a nucleotide polymer that plays a vital role in living organisms

Royal Navy Association, a form of auxiliary for the Royal Navy (United Kingdom)

Rochester Numismatic Association

Republic of New Afrika, a black nationalist community and political lobby group

RNA Showgrounds (or Brisbane Exhibition Ground), where Ekka is held

Royal National Agricultural and Industrial Association of Queensland, organiser of the Ekka

Royal Nepalese Army

Romantic Novelists' Association