No it is not posible to use the Multiplayer Mode in GBA games on the DS, you can only play GBA games in Single Player Mode on the DS, as the GBA games are not able to use the DS wireless features and the DS does not have a connector for a link cable.

No, it is not possible to be able to link Game Boy Advance games on the Nintendo DS. Unless the games you want to play have the multiplayer feature that only uses one unit, you can only play them as one player on the DS, as the GBA games are not able to use the DS wireless features and the DS does not have a connector for a link cable.