I've spent lots of time in Romania, though Cluj is one of the few cities I have not yet been to. I am not sure if the intended conference audience is international or meant to be residents of Cluj (though for my answer I'm assuming the former).

I do not have a specific name for you, but I would suggest to not limit name choices to necessarily require Cluj-Napoca or Transylvania. The conference itself and its location can help establish and showcase innovation in Cluj. Think of 10 popular tech conferences. Do any of them have the city name as part of the conference name? The city would always be listed right near the title, so anyone who hears about the conference will know where it is. It's fine to include the city, but if you keep your options open it may be easier to come up with a name. Hope this helps.