Airport departure tax is Rs. 500 for non-Indians, and it's included in the price of your ticket. The tax is the same no matter which country you fly to.
V.A.T., or Value-Added Tax, can be 1%, 4%, 12.5%, or nothing depending on the item purchased and the state where it was purchased. The V.A.T. is included in the listed price of items, except at restaurants and some hotels. For your hotel room, you will probably pay a service tax (around 12%), V.A.T. (12.5% and included in rates) and possibly even a luxury tax (10%). Rates differ from state to state.