You catch it at the top of snow point city.
Sorry to say, but no, you cannot catch a Palkia on Diamond version. You catch a Dialga on diamond, and Palkia on pearl. You would have to trade to get one.
you have to catch dialga on spear piller first
You cannot catch palkia in diamond and dialga in pearl but you can catch both of them in Pokemon platinum
You can only catch dialga in dimonid
catch Dialga and Palkia this is incorrect, you finish the game when you have completed both pokedex + nationaldex.
after you catch dialga
Spear Pillar
No you cannot. You can only catch Dialga in Pokemon diamond and platinum. Although you can only catch palkia in pearl and platinum.
This makes absolutely no sense. You catch Dialga at the Spear Pillar in Diamond or Platinum.
You can't catch Dialga in Pokemon Pearl. You'll need to trade for it.
20%.
You can't catch Dialga in Pokemon Black. You need to trade for it or transfer it from the older Pokemon DS games.