Gst rates

Hi,

Can you guys please helo me with the correct GST rates for the below mentioned scenario. 

A is a gold jewellery trader and also does job work. He receives Goods from manufacturer for job work. A then sends these goods to another job worker and gets the work done. Finally A sends the goods back to the manufacturer. 

What rate of GST should A charge to the manufacturer

1. @ 5% (For Gold Making charges) or 

2. @ 18%