This page of the Cyberpunk 2077 guide has a description of an important choice you will have to make in The Heist quest.
V, Jackie and T-Bug manage to get the Relic (biochip) but for a huge price. T-Bug was tracked during the action and Jackie got killed. Before you go to Dexter DeShawn, you need to decide what will happen with Jackie's body.
- Nowhere. Wait here for me: you will unlock an additional side job called Heroes.
- Take him home, to his family: you will unlock an additional side job Heroes.
- Take him to Vik Vektor's clinic: you will unlock additional dialogues and scenes related to Jackie in one of the later main quests. You won't be able to get the Heroes side quest but you will receive messages from Jackie's mother and keys to his motorcycle.
Can you save him?
Unfortunately, you can't do anything to save Jackie's life. Regardless of your character's skills or the dialog options you chose, the ending will always be the same - Jackie won't make it.