Question: is darth plagueis jar jar binks?
Answer: No. In Legends, Plagueis is specifically mentioned as being a Muun. Though his species is unknown in canon, it's safe to assume that Plagueis was not Jar Jar Binks. As a Sith Lord, there would be no possibility Palpatine, a.k.a. Darth Sidious, would have left his master alive.