These rates are applicable to transporter.
let me clarify you-
1. If Transporter charges 5% GST on its invoice, then he can not claim ITC.
2. If Transporter charges 12% GST on its Invoice, then he can claim ITC.
3. Or he can provoke burden of GST payment on recipient under RCM.
Now in your query, you are recipient of transportation service and not the transporter, You are paying GST under RCM. Hence as per Section 9(3) of CGST Act 2017 you will have to pay under RCM at the rate of 5% and you can avail Input Tax Credit (ITC)