Well that turned India-centric pretty quick! Mods in 3,2,1...
I can't help myself from adding this though: Bar Brother, it's a little short-sighted - silly actually - to suggest that additional aircraft or capability supplied to the PAF (J-10 in this case), is somehow an advantage to India.
A sale of J-10A/B to Pakistan means a greater number of aircraft India must balance against on it's Western front. J-10B in particular would bring added capability and complexity to the force arrayed against India in the West and at a minimum require India to adjust squadron numbers accordingly. Likely India would have to bring in additional assets like MKI in order to stay competitive. Those are assets that would otherwise have been deployed against China, and so would further stretch India's already shaky squadron availability numbers. Not favorable for India at all.
Financially China could offset/moderate the cost of export to Pakistan for J-10 or J-31 if the situation required, but I suspect the relationship with India would need to deteriorate further before that became an option