Thangmuansang made his competitive senior debut for the club on 4 December 2017 against Gokulam Kerala. He started and played the whole 90 minutes as Chennai City drew the match 1–1.[3]
NEROCA
On 17 June 2018, it was announced that Thangmuansang signed for NEROCA in the I-League.[2] He made his debut for the club on 7 November 2018 in a league match against Aizawl. He started the match and earned a yellow card in the 88th minute as NEROCA drew 0–0.[4]