The most common and most likely answer to this crossword clue is the 6 letter word KORERO
K
O
R
E
R
O
More clues leading to the result KORERO
Buddy explains!

The straight part
We know that "Wellington’s address" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case wellington’s address = korero.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does KORERO mean?
KORERO noun- Among the Māori people, a meeting to discuss something.