whether retailer is liable to pay GST Cess on sale of Tobacco products. and whether he is eligible for set off of input Cess paid on purchases

Reply— 

Compensation cess is levied on supply of Tobacco; therefore, the seller will charge compensation cess from the buyer of Tobacco. The GST cess on eligible product will be calculated according to the rate specified in the GST cess rate schedule and on the actual taxable value (transaction value) of the supply.

Credit of GST Cess paid can be utilized only towards payment of the GST Cess liability.