It isn't known if A Good Day to Die Hard director John Moore will return to the helm, or if writer Skip Woods will be back to craft the screenplay. Since A Good Day to Die Hard takes place in Russia, it makes one wonder what international locale John McClane will end up in Die Hard 6, or if he will be back in New York.
It is also possible that John McClane could go on an adventure with both of his children, Jai Courtney's Jack McClane and Mary Elizabeth Winstead's Lucy McClane. Mary Elizabeth Winstead appeared in 2007's Live Free or Die Hard as Lucy, and makes a brief appearance in A Good Day to Die Hard as well.
We should also mention that, back in 2010, Bruce Willis revealed that John McClane will retire after Die Hard 6, turning the franchise over to another actor. It's possible that Jai Courtney may take the reins as Jack, keeping the franchise in the McClane family.