The first problem is that the Mangrove Jack's Empire Ale yeast has an alcohol tolerance of only 8%. Using some beer recipe software, the amount of malt you used would lead to an alcohol percentage of 15%. Which means that your yeast will stop halfway the fermentation.
Second, the amount of hops is not matched to the original gravity obtained by using 6kg malt. Your IBU will be lower than for the original beer.
You could probably move your beer to a larger fermenter and dilute it. The problem here is if the original yeast will restart, but I suppose you might make an active starter with the same yeast to get the fermentation going again. Note that if you do this, the alcohol level will dilute to 4% and then increase again.
The problem with dilution is that this also dilutes your hop bitterness, taste and aroma. You could try to adjust this by boiling hops in water and then use this to increase the bitterness. Boiling hops in water has a better efficiency than in sweet wort.
And then you can adjust hop taste and aroma with a hop tea.
If you work clean and careful, I think that this should not be a problem. There is ongoing fermentation, and there is already alcohol, so if you clean your larger fermentation vessel, I would say that the risk of contamination is minimal.