You need to beat the Elite Four.
wake up raquaza in the sky pillar
after you beat the elite four the door at sky pillar should open
After you defeat Team Aqua and Team Magma's bosses, Wallace will take you to the Sky Pillar to awaken Rayquaza. Going through the incident in Sootopolis City, you can afterward return to the Sky Pillar to catch Rayquaza. This time, Sky Pillar will be more difficult to travel through, and Rayquaza is Lv. 70.
Its sky pillar..once u go to sootopolis,u need to go to the cave of origin..once ur there,talk to wallace,then head to sky pillar..he will be there waiting for u ..once u talk to him,he opens the door for u to catch Rayquaza.
First you should win the league then go to sky pillar that's it bhaskar amgain
Once you start the quest with the three legendaries then eventually Wallace will come along and help you open it. Don't Know
Find the legendary Pokemon Kyogre and groudon. When they fight go to the sky pillar awaken Rayquaza and talk to everyone in front of the Gym. It opens. But first to get to the sky pillar talk to steven than go.
No you do not need the regis to open sky pillar it is actually open before you even go to the Pokemon league and rayquaza starts on Lv. 70
beat the other gyms and it will open. It is giovanni -------------------------------------------------------------------------------------------------------------- DO NOT LISTEN TO THAT ONE You are supposed to get to the underwater cavern and beat team magma then go to sky pillar
Sky Pillar will not open until it becomes essential to the storyline. Once this occurs, Wallace will meet you at Sky Pillar and grant you entry in order to awaken Rayquaza. After completing this event, Sky Pillar will remain open. From the second visit onwards, the Mach Bike is required to navigate to the top floor. Just go there after you get through Groudon and Kyogre's battle.
do the Pokemon leuge then talk to the weather dude and he will open two new places to fly to groudons cave and the sky pillar then fly to the sky pillar at the top raquazer awates
well in ruby and sapphire you need to beat all gyms and then beat the elite four then it should be open but in emerald you only need to beat the 8 gyms