Two points, if the you are sure it is coming out around the area in the first photo, then to me that looks like the metal crimping arrangement that holds the plastic end tanks with the inlet and outlet pipes on to the aluminium core of the radiator, there is a rubber sealing mat/sheet between the two pieces, but for all intents and purposes if water/coolant is leaking there then a new radiator is required.
The other point is double check the water isn't coming down from the plastic hose clipping arrangement as the clip below it looks rusty as though water has been dripping down onto it for some time.
Once the release clip is pulled the hose with it's plastic end comes out to reveal an O ring rubber seal, incidentally when/if you fit the new radiator disturbing those O ring seals may cause another leak!
The reason I am aware of this is I have a Doblo that was leaking oil in to the coolant system from the oil cooler/oil filter assembly and any water pipes I had to disconnect wouldn't re seal as the O rings had been damaged by the oil.
The first two O rings I replaced came from Fiat Dealer at a cost of £37, they arrived two weeks later in a Fiat sealed bag marked PRC (Peoples Republic of China) so I wasn't impressed. As I subsequently needed to replace several O rings on the system I bought a Loctite O ring making kit, which although a fiddle worked and saved a lot of money.
To protect the new O rings from damage in fitting I used suitable silicon grease to aid assembly.
