My annual income is 13000. I have 3 dependent how much can I get back

WE don't know. That's what the TurboTax program is for. Complete your tax return using the program, and see for yourself. Most likely with such low income and 3 dependents, you'll probably get all withheld taxes refunded.

Any income besides wages? Are you married? You support 4 people on only $13k?
[Edited]  We ask these questions to make sure you are claiming all your income, and that someone else doesn't qualify to claim your dependents.

If you have income from working and children who live with you,,you may also qualify for the Earned Income Credit and the Additional Child Tax Credit.