T.D.S. on reimbursment expenses

Circular no. 715 dated 8th August 1995 states that section 194C refers to any sum paid and reimbursements charged in bills cannot be deducted out of the bill amount for the perpose of tax dedution at source. If such is the case, then how will the thershold limit of Rs. 20,000/- & Rs. 50,000/- will be applicable. If a bill of Rs. 21000/- is received from octroi clearing agent in which the amount of octroi is Rs. 19000/- and Rs. 2000/- are his clearing charges, will such transaction be liable for T.D.S. u/s 194C vide the circular no. 715. (Such octroi reimbursement is charged in bill itself and no other bill for octroi is provided).