GST ON DEMO CENTRE BILL

I HAVE PURCHASED A PRINTER MACHINE FROM MY SUPPLIER. HE NOW WANTS TO USE THIS MACHINE AS DEMO. HE IS IN DELHI & I AM IN MUMBAI. HE WANTS TO MAKE MY BUSINESS PREMISES AS DEMO CENTRE FOR HIS MACHINE AND IT'S PARTS & PRODUCTS. NOW I WILL CHARGE HIM FOR THIS SERVICE. KINDLY TELL THE SAC CODE & RATE OF GST TO BE CHARGED FROM MY SUPPLIER IN BILL FOR DEMO CENTRE CHARGES. THANKS