You have to go get the Ruby, and one of the Rockets will tell you the password, and then go get the Sapphire, and the Scientist will give you the second password.
By this point you will have both the passwords required for the Rocket Base on Island 5. Head to Island 5 and go through the Rocket Base, the Scientist is there.
you need to get two passwords the first one you get is in island 1 (mt ember) by 2 rocket grunts the secon you get is in dotted hole on island 6
The team rocket base is in Mahogany town.
First you go to the dotted hole on six island and get the ruby. Then a scientist will take it and give you the second password to the team rocket base, then go to five island to the team rocket base. Go threw it and find the scientist, u must battle him. after u beat him he will give it back.
It is underground
There is no team rocket base in Blue Rescue team. Unless you name your team Team Rocket.
If you have 100 Pokemon in your Pokedex (Caught of course), then you complete the other 4 islands available in the game complete with a Team Rocket base.
The rocket team are not on four island. there are two grunts up a ways of Mt. Ember north of one island, however the Rocket Base is on five island. It requires two passwords if you want to enter. Work that bit out for yourself.
Go to two island and go up keep going up and eventually you will find it the saphire.you get the Sapphire in the ice fall cave and you get the ruby in the dotted hole on 6 or 7 island
after beating the team rocket executive the murkrow knows the answer and you need to follow it through the base to the door
You don't on Island 6. You head to Island 5 and the rocket base where you will find him and the Sapphire.
I don't know you tell me Edit: Never answer if you don't know. They should have told you were the next password for the hideout for their base on Island 5, if not just head to Island 6, and head South until you come across the Dotted hole, head through that. After completing that you will be prompted to head to Island 5 for the Rocket Base.