Does anyone know the name of player who score 200 in single t20 game?
However, as pointed out by Ale in a comment, it has happened at lower levels, with Dhanuka Pathirana scoring 277 in a match in the Lancashire league. Mohit Ahlawat went even further playing for Maavi XI in a Friends Premier League match, scoring exactly 300 runs.
Mohit Ahlawat has scored 300 off 72 balls in a T20 at a match in Delhi in February 2017.
It was a local match, not an international or IPL game.