I predict Sri Lanka and perhaps even Thailand, Cambodia, and Laos. I wouldn't be surprise even Afghanistan might be interested in the future. JF-17 fighters are good for countries with a small military budget or land locked.
Let's analyze each country, case by case :
- Sri Lanka has small but diverse airforce of J-7, Mig-27 and Kfirs . Replacing those with one unified platform could be advantageous, but I you think they are more interested in ground attack then air combat (Sri Lanka mostly used their airforce in civil conflicts) . Therefore, I don't think they would be in a hurry to introduce JF-17 right away, especially until true capabilities of Block II, considering weapons integration, max payload etc are revealed.
- Thailand - I don't think so . Thai airforce traditionally use Western aircraft. They now have F-16, Gripen and F-5, so there is simply no place for JF-17 there .
-Cambodia - potentially biggest chance for export, as they rely on Mig-21 with very few of them actually operational. Of course, they would not be able to buy huge quantities of JF-17 , but it could be a start.
- Laos - they had some Mig-21s but currently those are not operational, and frankly looks like Laos has neither money nor political will to do operate modern supersonic fighters.