@tanguatlay,
Did he say "hello miss" or did he say hello to someone the speaker is calling miss (as in mr. or mrs.)? Right now, even with the improper period after miss, the sentence is ambiguous -- it's capable of two, equally valid meanings.
To avoid ambiguity, you need a comma before miss if miss is being used as a form of address: "I'll tell him you said hello, miss," he said. Otherwise, what you're saying is that the speaker will tell someone that someone else said, "Hello miss." And that doesn't make sense. :-)