Sub contractor work-expense head

Yes, you need to pay the ammount with all expenses.

what should be the expenses head?

Hi as per my knowledge 

Sub Contractor name under Creditors

For Payment

                 Dr.   Sub Contractor/Rajesh 

                Cr.    Bank A/c

Contractor Bill

                                      Labour Charges    ......... Dr

                                      GST    .......                    Dr

                                      Less TDS   .........            Dr

                                       Sub Contractor/Rajesh  .............. Cr