SAO PAULO, Oct 27 (Reuters) - Brazil"s treasury could raise up to 3 billion reais ($538.60 million) through its 5G auction next week if all available frequencies are sold, Abraão Balbino, chief of telecoms regulator Anatel, said on Wednesday. Fifteen companies and groups presented the required documentation on Wednesday to register for the auction, set for Nov. 4, including Vivo (VIVT3.SA), Claro and Tim (TIMS3.SA).