GTA in Sales Invoice

Item @ 12%gst 3 x 1000
Item @ 18%gst 1 x 1000
In single invoice. We also charge Packing Charges & Transport Charges as direct expenses in same invoice. What rate of GST should be charged on this direct expenses if 5% Gst charges by GTA as Tranport Charges?? 5% 12% or 18%???