FGAC - 11gr2

Hi all, Can you please let me know how to add fgac policy for the following piece of code that involves where clause and two tables? It is simple and easy when doing for  all  or selected columns of a table.

I will appreciate if you can list the steps. Also what is the difference between FGAC and RLS pkgs and what to use and when?

SELECT AMRCONF_PIDM, AMRCONF_COMMENT

  FROM AMRCONF, APRCATG

WHERE AMRCONF_PIDM = APRCATG_PIDM

     AND APRCATG_DONR_CODE ='PROS'

Thanks in advance,

VP