Reserve Bank Of India [RBI] — fake call and threat

Hi my mother got a call this morning from a guy named deepak sharma stating that he is from rbi and that he is going to block her account if the details were not given. She gave the details and luckily that account had only abt 2000 which was debited the moment the details were given. On confronting him abt this debit he threatened my mom to kill her if she complained against him. Please take due notice as this is a serious issue and kindly take the required steps to punish this guy.