Sale of goods on which input tax is already claimed.

1. You will pay the tax when you sold the particular Goods. 

2. If you want to choose Composition Scheme, you need to reverse the credit or pay the tax.

As I understand, since you have already availed input tax credit (under earlier statutory provisions), the same cannot be claimed again under GST. For sale of such goods, you will have to charge GST at the rates applicable and pay tax using Electronic Cash Ledger. However, you may adjust the same against Electronic Credit Ledger too provided you have made purchases during GST period, for which credit is admissible under GST.

Thank you Mam & Sir for your reply.

Does it matter if I have Excess VAT carried forward as on 30th June.

I was told by someone that if there is no excess VAT liability then I am not required to reverse the tax. 

Please explain in a little detail.