Only if you have the aurora ticket and mystic ticket can you venture onto birth island and navel rock.
Chat with our AI personalities
get a girlfriend....my friend....or, vote for ROMNEY
You can only get to Islands 8 and 9 in Pokémon FireRed through the use of cheating devices or through events which will give out the tickets which are needed to access the Islands however the events are no longer available.
I think only with Nintendo event
Islands 4 to 8 are unlockable by obtaining the National Dex and recieving the Rainbow Pass from Celio, beyond that all the other Islands cannot be reached as their events have long since expired.
You go to rout 8 and in the under ground path or go through SAFFRON city.