Obc certificate

My caste is kalwar which is in central list of Bihar , but in Bihar state list there is biahut kalwar , kalwar (kalar), kalwar (eraki) we all know that biahut kalwar comes under kalwar caste only , but what about ncbc do they accept biahut kalwar and kalwar as same caste or it's sub caste for the state of Bihar ?? And if I want kalwar caste certificate so can I get Central obc certificate without issuing state obc certificate because there is small difference in name of state list and Central list? And if I have my uncle Central obc certificate issued in Bihar can I use that central obc certificate to get my Central obc certificate in Delhi because I am permanent resident in Delhi and want migration Central obc certificate in Delhi on the basis of my father origin state ? Is it possible to get Directly Central obc certificate without having state obc certificate ? Is it legal to get direct central obc certificate on the basis of Central obc certificate of blood relatives?? Or state certificate is compulsory to get Central one ??