Based on meaning:
* Δαρείος (Dareios): This is the Greek spelling of Darius, a Persian king, which means "possessing goodness." It's similar to "Darin" in sound and might be a suitable alternative.
* Δωρεάν (Doreán): This means "gift," which could be a metaphorical connection to the name Darin if it has a special meaning for you.
Based on sound:
* Δαρίν (Darín): This is a phonetic transcription, using the Greek letters that sound closest to "Darin."
Ultimately, the best Greek spelling for "Darin" depends on the context and your personal preference. You can choose the option that feels most appropriate for you.