My client is doing finishing ,polishing and paint work on ply (wood) table tops owned by an export firm .My client recieves these wooden tops at his factory for work through delivery challan by exporter.My client purchases polish, paint material himself and applies them over wooden tops.The cost of these paint finishing turns out to be substantial.After finishing, paint and polishing, he returns the finished goods back.What is this categorised as , a job work or contract manufacturing.Sac code 998831 or which one if it is contract manufacturing. Plz tell Gst rate also for the same Plz help.