need deffence base

How can I make best deffence against wizard,goblin and archer pls tell me

There are many web sites with thousands of defense strategies for Clash. At TH6 your options aren't massive, but placing wizard towers and mortars in range of loot will help defend against goblins. Wizards being out-ranged by archer towers and cannons is the best defense against them.

There's always going to be someone to figure out a way to loot your base at TH6, though, as the defenses aren't very strong to begin with.

Try somewhere like http://clashofclansbuilder.com/

There's no defending a TH6. Build up your offense and steal more than you're stolen from!