Your cooked chicken should be safe for up to 4 days in the refrigerator.
However you can keep the cooked chicken longer for up to 4 months in the freezer.
When I have some leftover cooked chicken and want to keep it longer than 4 days I freeze it and then later on add it to my slow cooker with soups and other meals.
Uncooked chicken will only keep for 2 days before going bad in the fridge but the cooked chicken will last a few days longer in the fridge.