There are two wasy to obtain a Protector in-game, one on Route 11 and one on Route 13.
Route 11: down the southern waterfall, in the north-eastern corner past Pokémon Ranger Crofton.
Route 13: a man in sunglasses will give you a different item every day, one of them being a Protector.
Rhydon
Yes, you can get a Protector on Routes 11 and13.
you can't get a protector in Emerald. The Protector evolves Rhydon into Rhyperior, who is a Generation IV (Sinnoh) Pokemon.
In Pokemon Diamond and Pearl, a Protector can be found on Route 228. In Pokemon Platinum, a Protector can be found on Iron Island.
rhypirior loves protector
Rhydon holding the protector and traded will evolve into Rhyperior.
There are two waterfalls in route 11, if you have the HM Waterfall you have to go down the waterfall that leads under the bridge, you will see a ranger and near the ranger is the protector.
On Pokemon Diamond the Protector is a hold item for Rhydon. It is required for Rhydon to evolve into Rhyperior when traded while holding the Protector.
Give it a Protector item and trade it to a friend. (Dont forget to tell them to trade back!!!)
I believe that Rhydon loves the Protector, but I only found that out by trading it with the Protector on
catch a rhydon, give it the protector and trade it it will evolve into rhyperior and you will lose your protector
You can put protector on Rhydon, then when you trade it it'll evolve into a Rhyperior.