According to my Argentinian Friends. MiG-35 and Tejas are “very much not” in the running for the tender. The only two options are the F-16 and the JF-17. The F-16 honestly makes far more logistical and political sense for Argentina. Logistical because their current A4F use a bunch of components from the F-16 and political because then any issue remains in the west and China isn’t introduced into the south Asian fighter marker.
Currently the US has submitted a request to Britain to clear the sale of the aircraft, but with the British change in rulers it might throw a spanner in the progress if any had been made.
The original plan was to sell F-16 Block 40s to Argentina and locally upgrade them to block 50. Then it changed to offering them even older Danish F-16 MLUs, now they’re back to offering Block 40 (but maybe without the upgrade package). We’ve no idea of the munitions that will be provided but rest assured US will control their BVRs and AShMs. Also block 50/52+ and Beyond have British components, so they’re not an option anyways. Newest they can get is Block 50/52.
Obviously the F-16 has its inherent advantages in size and range, speed and maneuvering etc, but The Block 3 will easily outdo it in armament. That being said, it’s really still anyones game because Argentina has a say in his things go too, despite American pressure. So we have no idea who they will pick and when they will do it, if at all. There might just be so many political hurdles that we won’t see them buy a new fighter for several years still.