When is Blk III production likely to start?
Iranian government has previously shown interest in Su 30SM and J 10. No further progress is known at both ends.
Ah yes, now I remember ... there were reports stating Iran's interest in the Su-35 Flanker-Es. In fact, if my memory serves me right, the Iranian government was supposedly in talks with the Russian Federation about the procurement of Su-35 Flanker-Es, as well as an agreement on the license production of this aircraft in Iran. Mind you, these reports date prior to Trump pulling America out of the JCPOA deal with Iran. There isn't any indication whether this would in any way affect Iran's ability to purchase Su-35 Flanker-Es and setting up a production line on home soil, for the aircraft.
The way I see it, Iran has the economic clout to pull it off. Provided Iran has access to the international market for Oil & Gas trade. One can see why there is fluctuation on Oil prices for the past few years. Coupled with the economic sanctions on the Republic of Iran, Russian Federation and the trade war against the People's Republic of China. It's possible that such tact is intended to undermine the three countries ability to grow economically and as a consequence, modernize their militaries. But there is a possibility that Iran, Russia and China will be able to negate the U.S trade-war/sanctions.
JF-17 Thunder Block-lll's development is taking longer due to the fact that india has chosen Dassault Rafale, and more importantly, revived the MMRCA procurement program that has been dragging on for the past decade or two. Block-lll is understandably a major upgrade variant which would see the introduction of various new capabilities such as AESA, IRST & HMCS. Possibly even new engines, increased payload and who knows something else. Given the importance of the JF-17 Thunder program to Pakistan, the Block-llls won't be rushed. It may take slightly longer, but it's better to get it right and ready, rather than having to move on "Plan-B!"