Hi Murali,
I think you have maintained the posting indicator as 3- offsetting entry to GL account. These indicator we will use under reverse charge mechanism. Under reverse charge mechanism vendor is not liable to pay TDS, here receiver liable to pay the TDS. In that case we will use this option, maintain GL accounts for the key WIT & OFF. The entry will be:
Expense A/c Dr 100
Vendor A/c Cr 100
Service tax expense A/c Dr 14.5 (OFF)
Service tax payable A/c Cr 14.5 (WIT)
Regards,
Mukthar