Yorkies need to stay with their mother until 12 weeks of age. 6 weeks is absolutely too young.
If you're looking to rescue, try
Pet adoption: Want a dog or cat? Adopt a pet on Petfinder
I will warn you though that even rescues charge upwards of $150, generally. This is an
absolute steal for a dog who is already spayed/neutered, vaccinated, and HW checked.