Service tax exemption turnover limit under notification no 33/2012

dipak (ca final student) (25 Points)

29 December 2015  
i have query ,my client has provide residential constructions service during this first year we received Rs 500000/- as booking advance .so calculation of service tax i consider the following structure . booking advance ------5000000/- (-) abatement 75%-----3750000/- Taxable portion ------ 1250000 (-) small service 1000000 exemption 33/12 tax calculate on RS 250000/- so it correct or not please guide mie