You have to see all Pokemon Pokemon. But not the ones on nationaldex.
There is only one legitimate way to complete the Sinnoh Pokedex. To complete the Sinnoh Pokedex you must trade for the missing Pokemon with Pokemon Diamond, Pearl or Platinum.
Just go to Pokemon platinum central and click on pokedex and it shows you where to battle all the Pokemon in sinnoh.
complete the sinnoh dex and there
A way to complete your sinnoh dex is to battle every trainer, Nintendo made it so if you battle every trainer you will complete your sinnoh dex.
complete the sinnoh pokedex and talk to professor rowan.
I don't know if there is a code. But you can complete de Dex by seeing all Pokemon in platinum. All Sinnoh-dex Pokemon can be found ingame.?
Walk every square inch of Sinnoh and battle every trainer
You can either hatch them or run into them with the pokerader. To get the pokerader, you have to complete the sinnoh pokedex.
First complete the sinnoh pokedex, 210 Pokemon
You go round all of sinnoh and see every pokemon. It is easy to complete but will take a long time. You will not be able top catch them all without trading but you can complete it without trading
pelipper is the 120th Pokemon in the platinum sinnoh dex.
You can't. Sinnoh is only available in Pokemon Diamond, Pearl and Platinum versions which are set in sinnoh.