This is the 6225th most frequent Turkish word.
çetelerinin
"Of the gangs" or "belonging to the gangs."
The term 'çetelerinin' refers to 'their gangs' here and is used to indicate possession (their) related to gangs ('çeteler').
Çetelerinin yaptığı hırsızlıklar herkesin dilinde.
The thefts committed by their gangs are on everyone's tongue.
In this sentence, 'çetelerinin' again denotes 'their gangs', emphasizing possession specifically referring to individuals associated with the gangs.
Polis, çetelerinin elebaşısını tutukladı.
The police arrested the leader of their gangs.
Here, 'çetelerinin' highlights possession related to the threats caused by 'their gangs', emphasizing the association with a specific group of gangs.