Yes you can you have to beat the elite four and then get the national pokedex.
No.
You can go to professer Rowan's lab,but you have to beat the elite 4 first
You just need to see or capture all of the Pokemon in the first dex, which is a total of 210. It's not hard, most people do it around the time they get through the elite four. Though if you get through it and realize you're missing a Pokemon or two, like I did the first time, there's a lot of guides where you can find find the location to veiw the Pokemon so you can complete the dex. As for filling the national dex, I'm not much use there, sorry
he all the way in the back of turn back cave. you must beat the elite 4 and have the national dex. hope i helped.
No, you do not have to beat the Elite 4 to get the National Dex in Pokémon Diamond.
Have to beat the elite four.
Elite Clubs National Teams
The National Pokedex is given to you once the Elite Four is defeated.
they dont have any.
beat the elite four once
Beat the elite four.
You have to beat the Elite Four.
Augusta National
If you have 60 Pokemon or more go see prof.oak. He will give you the National Dex.Complete the National Dex.I'd see the Elite 4 again. They have new Pokemon.
Catch Arceus!!! 8 badges elite 4 National Dex/National Dex Upgrade Take down Giovanni at the eighth gym and then the Elite Four!
fill in the sinnoh pokedex and then the national one