Direct Translation: Where was he/she going?
It is a term used to tell someone that it serves them right after something bad/unfortunate happens to them. It is usually used when the person was doing something silly that they know could end terribly should anything go wrong.
The term was popularised after a video of Boti July Majuli went viral.
The term is now used by people who are not even Tsonga.
Alternative: Aya Kwini