So it said I got 6/6 wolf cubs in chest...... can I be one or what should I do?

It means that you have gotten this animal 6 times, the next time you get the animal you get acorns. Its like that for every animal.

The reason it says that is bc you are now able to have the max family number. If it said 4/6 you would’ve only been able to have you, your mate, and 4 pups. So now you are able to have 6.