[tamaikaj]

Support but the child lived with me last yr and this yr is living with her grandmother and not the mother what can I do?

[joypulv]

Assuming that you have had a paternity test, you sit down with your $$ numbers and work out how much the child needed for 11 years and what you can afford to pay the mother for all those PAST years.
If a court has ordered you to pay, you pay it.
We don't know how it is that you didn't know you were the father, but for the most part it doesn't matter.

[GV70]

but for the most part it doesn't matter.

Yes.It will depend on the state law. For example-in the state of Tennessee it is presumed that a father must pay CS from child's birth.I do not argue whether it is right or not-that's the law.