"Chaya" comes from a gypsi slang. In Germany explicit in Frankfurt/Main "Chaya" is another word for 'hot girl', bitch, etc... It is only used for women. Men are called "chab" or "chabo" instead, but this word can have different meanings, so search for the definition.
Gtown (a.k.a. G-ToWn or similar) is a District of Frankfurt (Germany) of which the more eastern part is a Ghetto. In this disctrict many people live in poverty, are jobless, do drugs, and beat up and rob other people.
A: I'm goin' back to the Ghetto!
B: You gonna stay in gtown all night?