This is the 81st most frequent Turkish word.
düzenlenen
"Organized" or "arranged."
Here 'düzenlenen' functions as an adjective describing 'otel', indicating that the hotel is one where an event was organized.
Eğitim semineri düzenlenen bir otelde gerçekleşti.
The training seminar took place in a hotel where an event was organized.
In this sentence, 'düzenlenen' is used to describe 'sergi', specifying that the exhibition had been organized.
Düzenlenen sergiye birçok sanatçı katıldı.
Many artists attended the organized exhibition.
'Düzenlenen' here modifies 'konser', applying the meaning of 'organized in a specific location or context'.