This is the 3232nd most frequent Turkish word.
gerçekleştirildiği
"Gerçekleştirildiği" means "where/that [something] was realized/carried out."
Here, 'gerçekleştirildiği' (was carried out) indicates that actions (the projects) took place successfully.
Projelerin başarıyla gerçekleştirildiği bir dönem yaşandı.
A period was experienced in which projects were successfully carried out.
In this sentence, 'gerçekleştirildiği' (was held) describes the location where the meeting occurred.
Toplantının gerçekleştirildiği salon geniş ve rahattı.
The hall where the meeting was held was spacious and comfortable.
Here, 'gerçekleştirildiği' (was held) conveys the idea of the festival being organized at a certain location.