Hi, the subject highlighted by Anthony concerns mainly the controlled airspaces...(in uncontroled airspaces, tcas is a plus but the main rule remains "see and avoid")..
To answer to anthony, an RA becomes the rule to follow in a potential conflicting situation, (whatever the atc instructions could be) and in europe atc is more and more aware about giving smooth instructions to avoid an activation of RA..
for ex..reduce the R/D or R/C while approaching a crossing traffic..
rgds