When I did my last renewal in the FNPT2, I was informed that every alternate renewal / revalidation has to be done in the aircraft. So if your last renewal was done in the sim, the next one will have to be in the aircraft, I am not sure from which date this rule applies.
(sorry, just realised Send Clowns has already stated this)
So if your previous renewal/ revalidation was done in the aircraft then yes you can renew in the sim.