How Do Transfer An Old Acc From An Old Device To A New Device

I Have tried using gamecenter and linking both don't work :( my iOS is 6.16 is there any other way to transfer my acc?

just make sure your Game Center login is the same, and Clash will ask you if you want to load your account. You don't need to use the "Link" feature unless you're trying to move from IOS to/from Android.

I use this feature all of the time to play multiple accounts on the same IOS device and multiple accounts on the same Android device.