Complex sentence: Including him, 13 out of 16 chief ministers belonged to the Congress party, including P. V. Narasimha Rao, who would go on to become the ninth Prime Minister of India.
Split into simpler sentences: Including him, 13 out of 16 chief ministers belonged to the Congress party. Among these is P. V. Narasimha Rao, who went on to become the ninth Prime Minister of India.