Just to add to what Machieng said - basically, any time you turn something into a location in Swahili, whether with the -ni suffix or a preposition (eg. katika) or prepositional phrase (eg. juu ya), the location can be used as the destination, the static location, or the origin. It's the verb that tells you how it is to be interpreted.
Ninakwenda nyumbani. I'm going home. (Destination.)
Ninalala nyumbani. I sleep at home. (Static location.)
Ninatoka nyumbani. I leave home / go out of home. (Origin.)
As I understand, Kutoka also means to leave. So either "you are coming from home", or "you are leaving home" (or in the plural: "are all of you are coming from home?", or "are all of you leaving home?").
Both translations can be roughly interpreted to mean the same thing, but in English there is a lot of subtle difference in the 2 interpretations.
Viz a viz "are you coming from home?" is asking if you are coming from a particular place (in this case home). Whereas, "are you leaving home?" is asking if you are in the process of leaving home. However, it can be qualified by adding "are you leaving home now?" or "are you leaving from home". I experience the swahili translations on this site as lacking in exactness. Is this just swahili, or this site, or has it been made simple for learning?