Hi Nidhi. I used Mike Griffiths' book, PMI-ACP Exam Prep, Second Edition, to study for the exam. Chapter 5 Adaptive Planning, starting at page 276, discusses estimation and techniques, one of them being Affinity Estimation.
The book doesn't discuss Relative Mass Valuation (RMV), so it would probably be a good idea not spending any time on it. I'd stick to studying the estimation items discussed in Chapter 5. Also, I know exam questions will certainly vary from candidate to candidate, but I wasn't presented with anything related to RMV.