We have created tax rates in sales->Taxes->Zone&Rates
with Rate Percent of xx.xx, Can we fetch this fetch this details programmatically before placing order for using it API.
I found an answer for this question,
$customer_tax_class = '5';
$rates = $tax->load($customer_tax_class, 'customer_tax_class_id');
$request = Mage::getSingleton('tax/calculation')->getRateRequest()->setProductClassId(2)->setCustomerClassId(5);
echo $percent = Mage::getSingleton('tax/calculation')->getRate($request);