Dioxygenase that demethylates RNA by oxidative demethylation: specifically demethylates N(6)-methyladenosine (m6A) RNA, the most prevalent internal modification of messenger RNA (mRNA) in higher eukaryotes. Can also demethylate N(6)-methyladenosine in single-stranded DNA (in vitro) (By similarity). Requires molecular oxygen, alpha-ketoglutarate and iron (By similarity). Demethylation of m6A mRNA affects mRNA processing and export (By similarity). 2-oxoglutarate + an N(6)-methyladenosine in mRNA + O2 = an adenosine in mRNA + CO2 + formaldehyde + succinate Binds 1 Fe(2+) ion per subunit. Monomer. Belongs to the alkB family.