How do you get araura ticket for Pokemon Sapphire?

You can't get an Aura Ticket in Pokemon Sapphire. The Aura Ticket is an item exclusive to Pokemon Ruby. It's used to access the Sootopolis City in the game, where you can battle the legendary Pokemon Rayquaza.

You can trade for an Aura Ticket in Pokemon Sapphire, but you can't obtain it through gameplay within the game itself.