As per Chaper V of IGST and Sec 2 (86) of CGST place of supply of goods other than supply of goods imported into or exported out of India, shall be :
a) where the supply involves MOVEMET OF GOODS, whether by supplier or a receipient or by any other person, the POS (Place of Supply) shall be the location of goods at the time at which the movement of goods terminates for deliver to the receipient; in this case MOVEMENT OF GOODS is relevant one.
c) Where the supply does not invlove movement of goods, whether by supplier of the receipeint, the palce of supply shall be the location of such goods at the time of delivery of goods.
In your given case as per clause (a) above movement of goods terminates at Delhi itself as it is ex-factory sale. Address of delivery is also mentioned in the Invoice as "DELHI", it is treated as Intrastate Sale and SCGT+CGST to be paid on such a transaction.
But if Insurance and freight paid by Delhi Supplier and Delivery address is mentioned on the face of the invoice is of "Mumbai" it is treated as Interstate sale and IGST + CGST is to be paid on such a transaction.
NB : This reply is based on my knowledge and belief based on the plain reading of the GST Act, pl. consult your CA or Tax consultant before act based on the reply. There may of chance of further debate on such a query if scenerio change.