Tds query on vendor invoice

I suppose it's on Contract basis. Then 194c and all in it will apply.

But sir we add margin in our advertisement bill and the purpose to earn profit to customer. Tds is required to deduct on expense
kindly clear my doubt

TDS is not deducted on expenses... it's deducted on payments with respect to the sections and the limits specified...if your service to vendor was on contractual basis and the payments exceeds 30000 (without GST) then they have to deduct...and since you said you sold the advertisement...youbare providing advertisement services and thus TDS will attract under 194C if payment exceeds the above limit (correct me if I am wrong)..or better consult a CA for more info