Kathe is a Deccani Urdu word, from Hyderabad, South India. It's a bit
complicated, but can easiest be described as
apparently. It is also used mockingly, the way you use "he/she says", a sort of scoff. It can be used out of curiosity as well.
Kathe can only be used at the end of a sentence, or after a word/phrase you choose to mock.
It is
pronounced as cu(as in cu-p) th(as in fai-th) ey(as in h-ey)