The oldest chickens I have now are around 4, I think, they might be 5, I am honestly not positive. They are still laying. The oldest hen I have had was a 10 year old RIR, she laid her last egg when she was 7 and then became a nasty egg eater and would teach the other birds to break open and eat eggs. She was very smart, she was older than me at the time and I would often leave the coop door open and forget to shut it at night, when the door was left open coyotes would come in and kill tons of birds, the hen realized this and soon started sleeping in the barn whenever the door was left open. She dropped dead when she was 10, I was pretty upset that the only chicken that was older than me died but at least the egg eating stopped.
My grandpa has some hens that are 13 years old, I am not sure when they stopped laying or if they stopped but I assume they could not still be going at this age.