I will try to summarize the answers in respect to your questions. The official timeline for serial production and delivery schedule was 2021/22 (Hisar-A/Hisar-O) but Idlib war reminded us about the importance of having national surface to air missiles so The government/institutes took precuations to accelerate delivery schedule. In this aspect, Army realised that Hisar-O is more vital than Hisar-A variants in terms of aversiveness/effectiveness so It was agreed that Hisar-A will be produced in limited number while remaining (previously planned) Hisar-A missiles will be enhanced into the level of Hisar-O (~30km range, 15km altitude) and Hisar-O missiles are being enhanced into the Hisar-O+ (~50km range, ~18km altitude). In paralel to this decisions, The production of Hisar-A and O missiles have been commenced for Turkish Army at present and Hisar-O+ will be revealed soon. Some Hisar-O missiles were deployed in Syria as well.
Atmaca has passed into serial production phase after completed qualification trials but This missile will still have French TR-40 engines and domestic equivalents will replace them in 2021 so Serial production will most likely commence with French engine.
Extended range version is not operational yet so If Bangladesh and Turkey sign a deal for Hisar missiles, It will be Hisar-A and Hisar-O at present.
Hisar is the name of a large surface to air missile family containing around 8 state of art missiles. When they were fully functional, The brother states will certainly benefit from these missiles and its technologies. G missiles (Goktuğ family) are in trial phase at present so Hisar-G is not an option for any costumers. What I see Bangladesh officials have shown serious interests to Turkish missiles so I see a great opportunity both state can benefit. Most likely, Turkish officials are giving some unknown capabilities about the systems that has completed qualification trials because That is the second time Bagladesh and Turkish officials came together and they are negotiating for Hisar missiles. I think We will form a good cooperation not only for Hisar but also network centric softwares called HERIKKS that is improving the effectiveness of SAM missiles.
