* "Sai-na" - This is the most common pronunciation, especially if it's a name of Polish origin.
* "Sye-na" - This pronunciation is also possible, though less common.
* "Sigh-na" - This is a less common pronunciation, but it can be used if it's a name with a different origin.
It's best to ask the person who uses the name how they prefer to pronounce it. If you're unsure, you can always say "Excuse me, how do you pronounce your name?" or "I'm not sure how to pronounce that, could you please say it again?"
Additionally, if you come across the name "Cyna" in a text, pay attention to the context. For example, if it's part of a Polish sentence, it's more likely to be pronounced "Sai-na".