As long as you know the name of the Pokemon you want, you should be good. Starting in X and Y, they changed the way the GTS works. Before, you could only request or search for Pokemon that have been registered as seen in your pokedex. Now, as long as you know the name of the Pokemon you are looking for, you can search for it, and request it. Just make sure you spell it correctly, as there are two Pokemon with similar names, those are Eelektrik (the evolved form of Tynamo), and Electrike,