Discrimination Free Git Platform Github, a plataform for collaborating on code implementation has blocked Iranian's based on the fact that they are from Iran. The excuse is that the blockage is to comply with US trade laws. 

Now my Iranian students cannot access their work. 

Does there exist an european version of github, which is preferentially likely not to adopt the same kind of ridiculous restrictions?
I would say that you best bet would be to have your university host a server running Gitlab, gitea, gogs, or something similar. It would take a bit of money and technical know-how to run the server, but at least you would be safe from embargos.