A right-arm fast-medium bowler, Mithun was called up to the India squad for the first Test against South Africa in 2009–10, only ten weeks after making his first-class debut.
Despite training at his father's gym throughout his teens, he failed to progress with his discus throwing, and a friend suggested that he join a cricket camp.
[4] Royal Challengers Bangalore's head coach Ray Jennings eulogised about him, describing him as an "express bowler", but he had a quiet IPL.
During the ensuing season, he displayed his credentials, claiming another five-wicket haul, and taking 47 wickets to finish as the highest wicket-taker in the 2009–10 Ranji Trophy.
[8] In November 2019, in the first semi-final of the 2019–20 Syed Mushtaq Ali Trophy, between Haryana and Karnataka, he took five wickets in one over, including a hat-trick.