The expenses should be treated as Rent on Machinery, as its purely hiring of JCB machine at your company. So the vendor who is providing this service will not come under RCM.
But in case
1. same vendor is providing labour along with that for loading unloading then it will be treated as of GTA services.
2. If invoice is raised inclusive of these hamali charges, GST will be paid @ 5% under RCM.
3.If charged separately, it will fall under manpower supply and RCM will not be applicable. Under FCM, rate will be 18%.
Section 9(3) of CGST Act read with Notification No.13/17-CT(R) dated 28.6.17 is applicable for the purpose of RCM.