It is an universal concept to raise sale invoice by seller. No one disagree with you.
Please ask this question yourself.
You are seller right.
Do you have a own transport facilities like cargo or shipping?
Does your buyer has this facilities?
Who does this transportation on behalf you?
When you despatch your material through someone vehicle or through transport companies. They will give a transport invoice. If Transporter register his business under GST, he will give you an invoice in RCM.
When you make payment to your Transporter. You should deducted TDS against payment. It fall under under 194C. Not with buyer.
Your buyer paid transport expenses against your invoice. Who provide transport service? You should TDS from them. Okay. Please let me know your thoughts. 🙏 Thanks