Unfortunately, you must migrate the regies from ruby or sapphire. You cannot catch them in pearl/diamond.
You can't find it at Pokemon Pearl you have to Transfer it from the GBA Games Ruby/Sapphire/Emerald via Pal Park
migrate it from Pokemon emerald ruby or sapphire
migrate from Sapphire emerald or ruby
no you have to migrate from emerald, sapphire, or ruby
Emerald.
You have to trade or migrate it from Ruby, Sapphire or Emerald.
migrate with emerald, ruby or sapphire
Get as starter in Ruby, Sapphire, or Emerald and migrate.
you can only get it from ruby/emerald/sapphire. i suggest cloning a registeel in emerald and then send the clone to pearl
You will need to migrate from Pokemon Ruby/Sapphire/Emerald.
You can not get groudon in Pokemon pearlYou can get it through migrating from ruby, sapphire, or emerald.
Registeel is unobtainable from Pokemon Diamond and Pearl. You have to migrate it from Pokemon Ruby, Sapphire, or Emerald.