maximum number of free account have been created on this iphone how solve this problem

Create the desired new account on another device

belonging to a friend/relative/co-worker or at a

location with publicly available devices such as

a library, Internet cafe, computer store.

There is no workaround to create another Apple

account on your iPhone once the limit has been reached.

Create the desired new account on a different device.

Are you trying to create Apple IDs for a school or business?