Service Tax may vary depending upon the type of service.
Let me give you a typical example:
Say, for First and Final Bill of a work, the bill amount is = Rs. 100000
Less:-
Security Deposit @ 10% = Rs. 10000
Income Tax @ 2.06% = Rs. 2060
Service Tax @ 2% = Rs. 2000
Cess @ 1% = Rs. 1000
Total Deduction @ 15.06% = Rs. 15060
By Cheque Amount = Rs. 84940