Nat was the son of Police Colonel Siri Kochahiran, former Governor of Yala Province. He completed his secondary education at Santi Rat Bamrung School (later renamed Santi Rat Wittayalai School) and studied Political Science and Public Administration at San Sebastián-Recoletas College in Manila, Philippines. He then served in the Department of Local Administration and Ministry of Interior, holding the position of District Clerk. Nat simultaneously acted in films and television, starting with the charity drama "Goodbye Nan Chao" on Channel 7 and the film "Mae Sri Phrai" with Petchara Chaowarat. He continued to appear in numerous films and television series, playing leading, supporting, and minor roles. After leaving the entertainment industry, he served in the civil service until his retirement in 2006 as Deputy Governor of Prachuap Khiri Khan Province. In 2007, he ran for Member of Parliament for Chaiyaphum Province, Constituency 2, under the Phuea Phaen Din Party, but was not elected. He married Nittaya Panathuk, former Vice President of the Prachuap Khiri Khan Provincial Red Cross and the Prachuap Khiri Khan Provincial Housewives Association, and had four children, one of whom is Jarusiri Puvanai, also an actress. In his later years, Nat continued to have acting roles periodically until he passed away from pulmonary edema on October 16, 2025 at the age of 79.