After three years playing for Castres, Kockott qualified for to play for France on residency grounds. He was selected for the France squad for the 2014 November internationals. He made his debut on 8 November 2014, coming off the bench in a 40–15 win over Fiji. He started his first game for France on 7 February during the 2015 Six Nations Championship match against Scotland; France won 15–8. He was selected in the France squad for the Rugby World Cup 2015.