You should change a 6 year old boys diaper every 2 to 3 hours although some 6 year old boys can go as long as 4 hours between diaper changes, depending on how much he wets or how often the 6 year old boy has a poopy diaper.
A 6 year old boy should have between 3 to 4 wet diapers per day.
Although the actual amount of wet diapers per day that your 6 year old boy should have will vary depending on how much he's sweating and how much he's drinking.
During cooler weather, when your 6 year old boy is not sweating as much, he may have as many as 4 to 5 wet diapers per day.
But in the summer time when he's sweating and is more active the amount of wet diapers your 6 year old boy will have could be between 2 to 3 wet diapers per day.
As long as your 6 year old boy is having at least 2 to 3 wet diapers per day, he's okay assuming he's staying hydrated.
Your 6 year old should have a poopy diaper either once or twice a day or once every few days depending on how much fiber your 6 year old boy has in his diet.
You should check your 6 year old boys diaper every 2 to 3 hours and change him when he's wet, but you don't have to change your 6 year old boy every time he pees as diapers can hold pee for a few hours or longer as long as it's not leaking.
For poop, you should change your 6 year old boys poop diaper as soon as you notice it to prevent rash and urinary tract infections.