Claim excise and vat

as a merchant exporter u can procure goods without duty and vat,

for excise follow procedure under notification no 42/2001CE (NT) for procure of goods without payment of duty 

https://www.cbec.gov.in/excise/cx-act/notfns-2k1/cent42c-2k1.htm

for VAT/CST you have to submit form H to the seller, and procure the goods without any VAT/CST.

Merchant exporter have two way for export of dutiable goods. Without payment of duty under rule 19 of central excise rule 2002 and rebate claim after payment of duty. 

As a merchant exporter you can buy without payment of duty (central Excise) with issue of CT-1 (after creation of Bond with Jurisdictional Assistant/ Deputy Commissioner of Central Excise). Therefore you dont have to pay Central Excise duty. If you buy with central Excise duty, you can claim rebate under Rule 18 of Central Excise Rules, 2002.

In relation to VAT/CST- you can procure export material without payment of VAT or CST under Form H. Under Form H, you can procure goods for export purpose without payment of VAT or CST.

If you procure material without H Form, by paying VAT, you can claim refund from the concerned state Government. But if you procure material from interstate and pay CST, there is no provision to get refund of CST paid by you for export. It is a cost for you. So always procure exported goods under Form H in order to manage your working capital.