The average 6 year old child can count as high as 200 and sometimes higher depending on how smart they are.
Some 6 year olds can count higher than others and that is normal.
All children are different and learn at different paces so if your 6 year old child isn't counting up to 200 or as high as they usually should then there's nothing to worry about.
I've known one 6 year old boy that could count as high as 300 which was amazing and another one could only count to 100 which was not bad.
The other 6 year old eventually mastered more counting and counted higher.
It's just that children learn at different paces and there's nothing wrong with the child if they are not counting as high as others.
We are all smart in different ways.