payment issues to the original supplier of goods

sir / madam (The case is discussed changing names and places for keeping identity private ) (the commodity is GST EXEMPTED) The case is : ( RAM from UP- he is a trader of commodity ) sells goods to ankur (KARNATAKA - also a trader of commodity) . Ram billed the goods in the firm name of ankur ( let say A dealers ) . Now ankur has some another firm ( let say B dealers. ) Ankur sold the goods to karan (a party in karnataka having a private ltd. company with karan enterprises pvt. ltd. ) ankur billed it from B dealers (with gst no.and weight slip) to karan enterprises pvt. ltd. and received full RTGS from karan enterprises pvt. ltd.. Now the problem is RAM doesnt got money for the goods as ankur is termed as a Defaulter . ques. are:1) what liability does mehta enterprises have now ? 2) is this case of 420 ? 3) can UP police come anyway and arrest karan in karnataka ? Thank you . Opinions would be appreciated.