I am working in a Packaging Machine Manufacturing company. The machines are made of different type of components and using Raw materials like Iron, Steel. Now the components used in the machine has different type of GST rate with different HSN code. But the Packaging Machin falls under HSN 84224000 @ 18% and spare of the machine falls under HSN 8422090 @ 18%. So, If we supply after sales spares to customer what would be the HSN? Actual GST rate as per HSN of as spare of machine under 8422090? Can we sell spare @ 18% though we purchase the same item @ 28%?
I need help in this matter.