Hello,
I just bought a Rhododendron X Hybrid Azalea from Walmart, and I want to move it out of its pot. The pot it is in is 8in in diameter, and 6in deep. I am wondering what size the new pot needs to be for this plant. I want to get one that is bigger than what is needed so I can add a little "pond" to it. I also want to grow the Azalea on top of a rock. Any help would be great.
Thanks.

The new pot can be any size you want.

if you are in the nortern hemisphere, do not do a proper repotting this time of the year. Uppotting is ok.

Slow down. It is not the time of year to do a re pot and as you have only just got this plant you need to learn how to look after it. Azaleas are usually re potted after flowering, although it can be done before. as for putting it over a rock it depends on the plant, if it is suitable and will take years to establish on the rock. It is not a usual thing to do with Azaleas. As for the pond no comment.