I hope not, because it took me forever to get the relicath needed in my Ruby game.
Assuming you already know the steps, I won't get into how to do them, but after compairing this guide and this guide, alongside my own experience, they're the same for RS and ORAS (Not Emerald; Emerald is in it's own world). You both need the Waillord and Relicanth, and you need to go to the proper locations (105, 111, and Route 120) and complete the required steps.
Also, to answer your question in the comments, an Oak Challenge is where you have to capture and fully evolve every obtrainable Pokemon before progressing in the game.
I hope this helps :)