Caste Certificate for migrated person and family

My father Bhokna Kerketta was born in the year 1952 In ranchi Jharkhand.At present permanent address in howrah since 1973 after railway appointment.His all documents like adhar,voter, ration card in west bengal.Grandson of his paternal uncle has st(Lohra) caste certificate in jharkhand.He has no blood relative live in west bengal.My father has digital caste certificate of blood relative from competent authority jharkhand.Sri Pawan Kerketta is the great grandson of my father's's paternal uncle.Pawan Kerketta has this digital caste certificatefrom competent authority of Jharkhand.My father has banshatalika with blood relative from gram panchayats pradhan with a witness.From Where my father get caste certificate Jharkhand or west bengal.From which state his family members get caste certificate?Lohra sub caste belongs to st in jharkhand and in West bengal.Please help.