The word has a couple of meanings depending on the context.

1. It can be used to show that you are laughing, similar to lol.

2. It can be used to say women or girls.

“Ja, sy is my Tletletle”🔥💕#TheQueenMzansi pic.twitter.com/NsODE75YML

— #JusticeForKwasa🌻 (@goaba_diale) November 17, 2018