According to Otter China will not sell J-10C unless Iran gives up nukes.
As I suggested before (possibly deleted by mods in the Israel-Iran thread) this is the optimal way to go about it. China would go all in on Iran under the pretext of denuclearization. The West wouldn't be able to say anything about it because that's been their stated main goal. Iran would need to go all in with China, no more dilly-dallying with the West or India though of course they can maintain cordial relations with them if desired.
The deal would be for more than just J-10CEs, it would be full suite of Chinese defense systems + economic investments. Once again though, Iran needs to go all in with a comprehensive partnership with China like Pakistan.