Complex sentence: He married in 1965 and has one son, namely, Suman Sarkar and a daughter, namely, Sudipta Sarkar, four grandchildren, namely Mishuk, Martin, Joy Tomas and Omya Sarker.
Split into simpler sentences: He married in 1965 and has one son, namely, Suman Sarker and a daughter, namely, Sudipta Sarker. He has four grandchildren, namely Mishuk, Martin, Joy Tomas and Omya Sarker.