Buddy, S24 Ultra has not yet received 

when will it be available for mobile in software update section ?

Galaxy J6 isn't compatible for games like PUBG. Even in low Grahics you wont experience lag free gaming even if your ping ms is low.

what about the date of release ?

Ya that happens because SAMSUNG always delays update for J6. Even PIE update Android 9 was released in the last week of scheduled month in 2019. So you would be getting it but with delay as of lockdown situation may also come into picture.