You should know that mods are un-official add-ons that are installed over the game. Because they aren't official releases, you might experience errors and compatibility problems. In this matter, if you want to use the mods, I suggest that you download and install the Oblivion mod manager. This tool will help you manage your add-ons and provide additional information about them, like the game versions that is required to load a certain mod. Also, you should check the NexusMods website and access the Oblivion area.