Authentication of non criminal certificate

Hi, i am working in China, i want to change my comoany to another company in another city in PRC. for which they need my non criminal certificate which should be authentication by PRC embassy in Delhi, i would like to know the process of authentication, and how much time and cost it would be ? Is it possible to do my non criminal ceritificate authentication In PRC Embassy Delhi without me? As i am now in PRC, so is it possible that my friend or any of my family member can do this ??