SH.MANOHAR KALBURGI Ji,
Re-examined the whole issue. Relevant extract of Board's Education Guide is applicable only if your firm is in the specified category. Your firm is not in the specified category so you are not required to pay Service Tax on the amount of freight paid by your firm as opined by Sh.Ganeshan Kalyani Ji. Proprietorship firm, being in unorganised sector is not covered under RCM (Notification No.30/12-ST dated 20.6.12).
Further, if GTA is unregistered by virtue of small scale exemption (or on some other factor), then consignor or consignee is required to pay Service Tax. If both consignor and consignee fall under unorganised sector, then GTA is liable to pay Service Tax. In this scenario, if Consignor falls under the specified category, Consignor will pay ST on the amount of freight. If both consignor and consignee fall under unorganised sector (out of specified categories), GTA is required to pay Service Tax under Forward Charge Mechanism. GTA will have to verify the status of consignor and consignee whether they are covered under specified categories or not.
Now GTA can also avail small scale exemption of ₹ 10 lakhs depending upon turnover in the preceding year.If GTA is entitled to avail small scale exemption, he will not pay ST under FCM.
So in this scenario, it is presumed that GTA is unregistred because of availing small scale exemption. He will not pay ST. Your firm is not in specified category. You will not pay tax.
Now liability to pay ST is on Consignor (if that person is covered under one of the specified categories.)
So to be on safer side, your duty is only to verify the status of Consignor and keep it on record with you as documentary evidence in order to avoid any future complication, if any arises.