you need 150 Pokemon to get the national pokedex
You have to trade with firered or leafgreen to get the national pokedex.
Yes, but you must have the national pokedex
You must have the National PokeDex to capture Heatran.
To get the National Pokedex, you must have seen all Pokemon from the regional Sinnoh Pokedex after beating the Elite Four and Champion. After doing that, go to Sandgem Town and talk to Professor Rowan in his lab and you will get the National Pokedex.
Beat to elite four and receive the national pokedex (to receive the national pokedex your must at least see all of the Pokemon in the sinnoh pokedex that you have already).
you must talk to professor birch after beating the Pokemon league
To get the National Pokedex, you must see all of the Pokemon that are in your regular Pokedex. You do not have to capture all of the Pokemon, but merely seeing them is enough, and it doesn't matter what gender the Pokemon is either.
if you mean national pokedex then you must complete your normal pokedex and show it to the professor. if you already have a pokedex and think that there is an international one then you are sadly mistaken
you must beat the Pokemon league and complete both the regular pokedex and the national pokedex
Mysterious fossil is not a Pokemon. Only Pokemon are listed on the Pokedex. You must revive the fossil in the Pewter City museum.
You must get the national pokedex first then go to iron island
You can get it inside Snow Temple but first you must have the national pokedex...