Is IGST applicable or not

We are a firm registered in Rajasthan (Jaipur) for the sale of LPG gas cylinders. We supply commercial cylinders (18% GST) to a firm in Jaipur, which is registered in Uttarakhand, and is working in Rajasthan (Jaipur) on a contract basis.

Whether IGST will be applicable or CGST/SGST