Where do you get The fossilles in Relic castle Pokemon white?

You can't actually get fossils in Relic Castle in Pokémon White. Relic Castle is a location in Pokémon Black, not White.

To get fossils in Pokémon White, you need to visit the following locations:

* Undella Bay: You can find the Old Amber fossil here.

* Route 17: You can find the Old Sea Shell fossil here.

After obtaining the fossils, you can revive them at the Revive Fossil Machine in Undella Bay. This will allow you to get the following Pokemon:

* Old Amber: Aerodactyl

* Old Sea Shell: Omanyte

Let me know if you have any more questions about Pokémon White!