service tax

GST not applicable as of now. All the payments made/to be made, till implementation of GST will attract only ST.

thank u sir for u r kind answer ,Dhirajlal Rambhia     

thank you sir , for ur kind reply,
l have paid service tax to builder in 2015 , 12.36%(effective rate at 3.09% on total agreement amount) now its 3.75%, or 4.5% on agreement value, can builder ask for this increased service tax, though i had paid already
at 3.09% on agreement value, i have receipt provided by builder,
looking for u r kind answer and suggestion,
thanking you sir.

The rates of service tax  would be applicable as on the date of payment due to builder. Even though you may have paid in advance, but if any addition tax levied on the date of payment, you will be charged the difference in ST. (only on the portion of payment, and not over full value)