Does anybody know is it possible to buy this gasket for air filter housing in Romania.

Yes, you have three choices: either go to a scrapyard (search "dezmembrari" and a city on google for scrapyards near you), go to a Renault/ Dacia dealership or find a small "Piese auto" shop, but try to find one with some air filters, oil filters and a computer in it, they will be able to order the gasket for you. If you're lucky, they'll have it in the same day. Otherwise, you might have to wait a while.