You will definitely have to pay the Import Duty and you can look at the same website or Duty Calculator to estimate how much that would be.
As far as India export taxes are concerned you can take a look at the Export procedure taxation website to get some idea but unless you are planning to do this yourself I would either contract with a shipper that would handle the procedures for you. Or have the manufacturer bake in the export taxes (if any) directly into the cost of the garments they ship you.
I would also contract with a customs clearing agents here in the US like Cleared and Delivered (used as an example only) to handle your customs clearance and delivery to distribution site.