Once you have the card key go to floor 3 and enter the card key door on the left near the rocket grunt go toward the portal you will be sent to floor 7 defeat your rival then talk to the guy nearby then go to the portal below you this will lead to floor 11 where the boss rocket is. Defeat the rocket grunt then open the door and defeat the boss rocket then talk to the silph co president he will give you the master ball.
There are various Pokémon available to capture inside the mansion in FireRed version. For example, there is Koffing and Grimer.
By defeating team rocket in saffron tower
Go to Celadon City then go inside the Celadon Mansion look for an old lady on this floor talk to her and she will give you some Tea give this to the security guards that block you from going to Saffron City they will take the Tea and allow you to go to Saffron City. she give me nothing. she just said: my dear pokemon keep me company.meowth even brings money home! that's it..
inside the rocket warehouse on the fifth island.
you go to the seafoam islands and go inside and look around for a slowbro or slowpoke you will find one eventually
There are various Pokémon available to capture inside the mansion in FireRed version. For example, there is Koffing and Grimer.
In Saffron city there is a house in the bottom right corner. The man inside will be sitting on the right side of the table inside the house. Talk to him and he will give you psychic
On 1 Island, he's standing next to the trading machine inside of the Pokemon center.
To get the TM psychic go to saffron city and go right from the Pokemon center there will be a house with a mailbox it says MR psychic go inside and talk to him he will give you the TM now teach it to a Pokemon that can learn and there you go you have psychic.
You need to beat the Team Rocket inside the Silph Co.
Silph Co. is in Saffron City. Go through the City to the GIGANTIC Building, go inside, and then go to this web page for help then on: http://bulbapedia.bulbagarden.net/wiki/Silph
Inside Seafoam Islands.
Go to saffron city and go toward the Pokemon center go to the right until you find house near a mailbox go inside and talk to the guy you will get the TM Psychic.
its inside the mansion
Nothing but Zubat.
Simply go inside.
u can find growlithe inside Pokemon mansion, which is on cinnebar island.