Gst rate for civil labour contract work

Sir,

01. What is the GST Tax Rate for Civil Labour Contract Work ?

02. Can i claim input GST Tax for previous month invoice ?

    Ex: Input Purchase Invoice Date : 05.01.2018 , GST Return Filing month March-2018.

03. We give sub contract work to civil labour contractors. One contractor give invoice with GST 12% & another contractor give invoice with GST 18%. Which is correct ?

04. What is the GST Tax Rate for Sub-Contract work with Material + Labour work ?

05. Can we make payment directly to labour (or) vendor on behalf of Sub-Contractor ? As per IT it is allowed ?

Thanks & Regards,

M.Shanmugasunadram