Gst for civil contractors

for civil contract work govt. department deduting some tax like inometax 2% GST 2% Labour cess 1% and other misc. charges like royalty, water chargers etc. My question is that for turnover calculation gross amount of bill will be taken or after deduction of  all taxes rest amount?

Purchase of non GST item DIESEL will be adjusted in gross turn over(purchase of diesel about 10-15% of gross turnover)