This is the 15779th most frequent Turkish word.
toplandığı
"Toplandığı" means "the place or instance where it was gathered/assembled."
The word "toplandığı" is used here as a part of a relative clause indicating the place where people gathered.
Halkın parkta toplandığı görülüyordu.
It was observed that the crowd gathered in the park.
The word "toplandığına" indicates a completed action referring to the documents being collected.
Belgelerin bir klasörde toplandığına emin oldu.
He ensured that the documents were collected in one folder.
Here, "toplandığı" is used to describe a habitual action related to meetings being convened in the hall.