How do you catch to the seventh island in Pokemon firered?

Sevii Islands ( Islands 4, 5, 6, and 7.)

First goto One island. get the ruby (or sapphire i think) and bring it to Celio (bill's pokenerd friend) he will give you a rainbow pass. you can now access islands 1 - 7. but you gotta have beat elite four and have national pokedex

National Pokedex

Beat the Elite four. Make sure you Owned 60 Pokemon in pokedex. Go to professor oak. He will give you the National PokeDex.

Sorry I'm not singed in but this is Kyogre286 writing.