Lower deduction of TDS for Vendors

Dear Experts,

My client requirement is,when the vendor gets an exemption certificate from income tax authority for a certain percentage for a particular Threshold limit after that the system has to calculate the normal TDS rate.

I have gone through the different thread but could not find the proper solution.

Please guide how to configure the system to calculate TDS for a lower percentage upto the threshold limit...after that normal TDS should apply.

Regards,

Venkat.