Jishnu was born in Kannur to Malayalam film actor Raghavan and Sobha. He did most of his schooling in Chennai. He also studied in Bharatiya Vidya Bhavan, Trivandrum. Jishnu had achieved best student award in his school days and joined NIT Calicut to do his B.Tech in Mechanical Engineering.Jishnu has a younger sister Jyothsna who is an archeologist. Jishnu is married to Dhanya who also graduated from NIT Calicut. Dhanya is now an architect in Chennai.After completing his engineering he was selected in campus interview to Emmerson and was appointed in New Delhi as an Engineer.