So which one is actually official one? I can't describe what "official" mean here, maybe the one that actually came from reddit or the one with more subsscribers or one with more activity ?
Also Why there are multiple copies of same community in different instances? Isn't the whole point of lemmy is that it is federated?
There is no official. It is just a bunch of people with the same idea.
Maybe someday all the sub's with the same name come together and choose an instance where they work together, the that would be the official one. Official in a sense that it has the most users.
In the sense of most users you can see that by the number on the left. 14k for the first, so per your definition that would be it.