New York — Twelve defendants caught up in an investigation into rigged poker games allegedly involving NBA figures and members of the mafia are set to make plea agreements in the federal case, prosecutors said Wednesday. They said the formal plea deals will be entered in the coming days. The names of those pleading were not released.Prosecutors also said nine other defendants are still in discussions about possible plea agreements.All 31 defendants in the case — including NBA Hall of Famer turned coach Chauncey Billups and former player Damon Jones — had an appearance Wednesday in federal court in Brooklyn.A source with knowledge of the discussions said Billups is not among those expected to take a plea deal. Billups, Jones and the others have previously pleaded not guilty.The defendants were snagged during a sweeping FBI crackdown on alleged illegal gambling schemes involving poker games and sports betting in October.…