Season 3 of Kingdom covers starting from the chapter 261.
The following arc have been covered:
It began airing on April 5, 2020 but went on delay following its fourth episode due to the coronavirus pandemic.
The anime will resume from April 4, 2021 but it will restart his broadcast from episode 1 of season 3 again.
Qin is suddenly invaded by Chu, the great southern state. While the country prepares, not without concern, to face one of the most powerful of the Seven Warring States, everything seems to indicate that the state of Chu is not their only enemy and that from now on, the survival of the kingdom of Qin is at stake...