How Do I Train My 6 Week Old Chihuahua Which Mixed With Yorkie To Be House Broken?

NEVER rub a dogs nose in it's waste, and don't spank either.  At 6 weeks your poor puppy should still have been with its mother and siblings.
I see you asked this a month ago so now your puppy should be 11 weeks old and on its way to being house trained.
The key is for YOU to learn the signs your puppy gives you that it needs to go, and for you to take it outside and praise it for doing it out there.  Ignore mistakes - it was your fault for not seeing the warning signs.

If you don't want it to go to the restroom in the house, every time that it does (make sure you catch him doing it, and punish him/her within the next few min.) put his/her nose in the spot, spank it on the butt, and then go outside and pet him/her out there.  If it doesn't go, then put him/her in a cage and in a few min. Take it outside again.  Repeat this until they go, and then praise it very well.  This might take a few days, not until they go pee, but until they get the fact that they need to tell someone to let them out so that they can go to the bathroom.