Whether gst is applicable?

MR. A sending the material for repairs of his car . Under gst the supply should be done in course or furtherance of business so Mr .A sending material is not in course of his business . so its outside the ambit of gst. however gst here would be charged when a.) Mr A would have purchased the materials from the registered dealer b) if any gst was charged for the repairs.

Thank you Madam