Clarification required for charging vat or cst

Could you please confirm whether tax is charged based on the party's billing address or shipping address? For example, if a company's office or billing address is in Bombay and they have another office somewhere in Bangalore or Delhi etc. where the goods are to be shipped/delivered, then do we have to charge them VAT or CST? On the other hand if their billing address/office is in Delhi or Chennai etc. and the goods have to be shipped/delivered locally in Bombay, then is VAT or CST applicable? Please clarify the same?