GST APPLICABLE ON LABOUR CESS AND SEIGNORAGE FEES - Goods and Services Tax - GST

Dear Sir, I have got work contract from Bihar Government for various work. In Some work contract Contract Value show as follow Cost of Work = Rs.100 GST @12% =Rs. 12 LABOUR CESS 1% =Rs. 1 SEIGNIORAGE FESS = Rs. 5 TOTAL WORK CONTRACT =Rs.118. MY QUESTION IS I AM LIABLE FOR GST ON LABOUR AND SEIGNIORAGE FEE OR NOT. BECAUSE IN AGREEMENT LABOUR CESS AND SEIGNIORAGE FEES GIVEN BY BIHAR GOVERNMENT SEPARATELY AND THAT AMOUNT DEDUCTED BY DEPARTMENT . But GST Officer demanding gst on Labour cess and Seigniorage fees. I ALSO RAISED THE GST INVOICE TO BIHAR GOVERNMENT AS FOLLOWS COST OF WORK DONE =Rs.100 GST@12% = Rs.12 LABOUR CESS = Rs.1 SEIGNIORAGE FESS = Rs.5 TOTAL VALUE OF INVOICE =Rs.118