Thank you for your question. This is a really tricky issue. As you might know, Norther Cyprus is an unrecognized entity, meaning no state (other than Turkey) can deal with it at the state to state level, and there is a very complex arrangement regarding private documents (this was the topic of my PhD).
This is why the answer to your question is:
-> if they establish title to property they may sell the land, to anyone who is interested in buying it. They would receive Turkish Liras, which is good because they can be exchanged internationally;
-> however, it is extremely unlikely that they would be able to exchange it for land in the Republic of Cyprus (the South), because most Southern legal institutions would not make such a contract, nor would the northerners either. Plus, given the violent separation of the two communities, it is unlikely that there are persons in a similar situation wishing to trade southern for northern land. If you do find such a person, an exchange could, however, be structured as two sale contracts. One done in the north, your land for their money, and one done in the south, their land for your money, with the money then being compensated privately so that in fact it does not change hands. In this way, you would avoid recognition issues.
I hope my answer is helpful and look forward to your rating, which is essential to my activity.
Dr I L Vlad