Place of supply

Place of supply would be Delhi, since the supply does not involve movement of good, therefor, POS will be the location of goods at the time  of delivery to the recipieny. In your case, it will be Delhi only.

Place of supply is the place where the goods are delivered to the buyer. In your case since the supplier is located in Delhi and the buyer has received the goods in Delhi only from the supplier of the goods. The place of supply is Delhi and it's an intra state sale. CGST and SGST will be applicable on such goods. The fact that the buyer belongs to J&K is irrelevant here.