FRIf I got an exemption for FA, do I still need to revise it for FR?

You are assumed to have a level of knowledge and skill associated with passing or being exempt from previous subjects. Please see the following link's answer for how to recap knowledge efficiently- https://opentuition.com/topic/should-i-accept-all-of-the-exemptions/

I would urge you to also read the following article- https://opentuition.com/acca/plan-your-acca-exam-journey/