It took place from 28 October to 20 November 2021, with 37 teams competing in six round-robin divisions.
Railways, who were the defending champions, won their 13th one-day title, beating Karnataka in the final.
The top two teams in each Elite Group progressed to the knockout stages, along with the top team from the Plate Group.
The five Elite Group winners progressed straight to the quarter-finals, whilst the remaining six teams competed in the pre-quarter-finals.
If points in the final table were equal, teams were separated by most wins, then head-to-head record, then Net Run Rate.