As others have said, your father cannot claim you as a either a qualifying child or qualifying relative dependent. If somehow he could (e.g. your taxable income was less than $4000), you would not be allowed to claim a qualifying child of your own (a dependent can not have a dependent). You are also not allowed to claim EIC based on children who are not your dependents. There are a couple of exceptions (described in the comments), but they don't apply to your situation.
If you and your children live with your father, he can claim one or more of your children as HIS qualifying child.
