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 (PubMed:23177736, PubMed:24778178,PubMed:24616105, PubMed:24489119). Can also demethylate N(6)-methyladenosine in single-stranded DNA (in vitro)(PubMed:24616105). Requires molecular oxygen, alpha-ketoglutarate and iron (PubMed:21264265, PubMed:23177736, PubMed:24778178,PubMed:24616105, PubMed:24489119). Demethylation of m6A mRNA affects mRNA processing and export (PubMed:23177736). Required for spermatogenesis (By similarity).