The most common and most likely answer to this crossword clue is the 6 letter word PARLEY
I've seen this crossword clue in Financial Times
P
A
R
L
E
Y
More clues leading to the result PARLEY
Buddy explains!

The straight part
We know that "discussion" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case discussion = parley.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 PARLEY mean?
PARLEY noun- A conference, especially one between enemies.
- To have a discussion, especially one between enemies.