Succession certificate

Hi, share holder is US citizen died in US. She has a nephew ( legal heir), who is indian citizen living in Bangalore. She has left with a will in his name. She had some shares of Indian company listed in stock exchange. Company registered office in Chennai. Now would like to know, where he has to obtain succession certificate from (jurisdiction of civil court) and family tree from revenue department ( jurisdiction). Asking on behalf of my frd. Your valuable comments and suggestions much appreciated. Thanks in advance.