What does a FR grade mean on your college transcript?

There is no standard "FR" grade designation used on college transcripts. Transcripts use a variety of letter grades (A, B, C, D, F), plus sometimes pass/fail (P/F), incomplete (I), or withdrawn (W). If you saw "FR," it's likely a non-standard abbreviation specific to that particular college or university. You would need to check with the registrar's office at that institution to determine what it means in that context.