The phrase "a discussion on which" is correct and usable in written English.
It can be used when referring to a specific topic or subject that is the focus of a discussion.
Example: "We had a discussion on which strategies would be most effective for our marketing campaign."
Alternatives: "a conversation about which" or "a dialogue regarding which".
During a discussion on costs, which are estimated at about £2m for both sides, the court heard that initially Karpov had claimed he had a "substantial reputation in the jurisdiction of England and Wales" to defend, but that later he withdrew this, agreeing that he did not have reputation prior to publication.
"Now there is a discussion on this, which is great," she said.
In the international context there is an open discussion on which kind of electromechanical gait training device is more effective.
There is an ongoing discussion on which upper limit, 100 mg/kg versus 50 mg/kg, provides the best accuracy in diagnosing IBD [ 37].
With so many smartphones out there now capable of making cinema-grade videos, there's an endless amount of debate and discussion on which one comes out on top.
(To this end, Bridle has started a site called Open Bookmarks, a discussion forum on which people can hash out the basic rules of capturing electronic metadata).
Leaving the BBC in 1999, he moved to Sky Sports, where for seven years he presented Jimmy Hill's Sunday Supplement, a discussion programme on which he was joined by three football reporters.
He is said to think that time would work for him, that Danzig was a good subject for discussion, on which he would succeed in dividing opinion in France and in England, and that Poland would herself one day come and ask for mercy.
We drafted an abridged report of the discussion on which the participants commented.
What's at stake here is a discussion on urban regeneration – which is connected to, but distinct from, economic revival.
