In the original release of Final Fantasy VII, acquiring a summon materia won’t be possible until you are out of Midgar but in Final Fantasy VII Remake, several become available in the game.
There are a total of 9 summon materias that you can acquire in Final Fantasy VII Remake and that includes the three that are available as a bonus for pre-ordering it or included in the Deluxe Edition.
Find below the summon materias that you can acquire in Final Fantasy VII Remake:
You can get Ifrit at the end of Chapter 3 where Jessie will give it to you as a gift.
Chocobo and Moogle
As soon as Chapter 6: Light the Way starts, you can find the Chocobo and Moogle Materia behind a fan, but it won’t be accessible until later in the chapter. Once you get access to the terminal, turn it off and it will give you sixty seconds to clear all the enemies that it spawn. When it’s all cleared, you need to activate the terminal and then head through the door ahead of you. The Summon Materia should be there at the end.
Shiva and the three remaining summon materias can be acquired by completing Chadley’s Battle Intel Report. For Shiva, you need to complete Battle Intel Report 5.
Note: Chadley’s Battle Intel Report missions can be done as soon as you are able to take on missions in Chapter 3. Make sure as soon as you complete the Battle Intel Report, you will turn it to him right away to get your rewards. Battle Intel Report missions vary from missions like asking you to trigger stagger for a certain amount of times, inflicting elemental damages, and more.
Complete Battle Intel Report 10 from Chadley
Complete Battle Intel Report 15 from Chadley
Complete Battle Intel Report 20 from Chadley
Available as a standard pre-order bonus
Cactuar and Carbuncle
Included in the Deluxe Edition