In order to access the Lasombra and Toreador clans, you'll need to buy the Shadows and Silk add-on pack, which costs £18.69/€21.99/$21.99. And as far as I can tell, you won't be able to access these locked clans otherwise. If you don't pay, you'll only be able to access the default four: Brujah, Tremere, Banu Haqim and Ventrue.
