Chosen Solution

I want to ask about my iPhone 4S, current version is IOS9 ,and then how I can downgrade to IOS6 . It is due to when I upgrade IOS 9 my IPhone will become lag so I want to downgrade . Got someone got solution to help me ?

You need to wait for you current firmware to be jailbreakable and you can use tools to help trick the device into thinking ios6 is signed.