The exhibition would be held at Naqueri-Betul in South Goa, close to the coast.
Union Defence Minister and former Goa Chief Minister Manohar Parrikar would inaugurate the DefExpo, being held in the coastal state for the first time.
The land was acquired for an industrial estate; it has been temporarily allotted to the Defence Ministry for the expo.
The locals are opposed to the event claiming that they were not taken into confidence. Petitions have also been filed before the Goa bench of Bombay High Court, opposing it.