Q: Does 'I'm ok.' mean yes or no? I understand in the restaurant if the server asks whether you want ketchup or not? You answer I'm good. Thanks.. That means no. However, I heard when someone was asked would you like ...?, and they answered I'm ok.. And the first person took it as rejection. Now I'm confused. Does I'm ok. really mean yes or no?

A: This question seems to call for opinion, so here's mine:
To me it seems that I'm ok / good / fine indicates that I have no need of anything at the moment. So if I'm being offered something, it basically means, No, thank you -- which would be a more formal and polite expression to use. Some people might take that as "rejection", although I doubt that is the real intent. On the other hand, if people would use the more formal and polite expression, it might reduce the chances of misunderstandings.
PS: You might want to ask about this topic on Interpersonal Skills SE.
