Billing not exceeding 50,000 Rs. in a Year

Hi all,

If an Advertising Agency raises  bills on client in a particular F.Y, one exceeding Rs. 20000 but total not exceeding Rs. 50,000 in a year. Whether Client would deduct Tds on Entire Bills raised on him or only on the abovementioned bill?

Also, while computing limit of Rs. 20,000/Rs..50,000 for applicability of Sec. 194C, Whether Service Tax component mentioned in the invoice would be considered?

Thanks in Advance