After discovering he has a son, an exiled gangster must confront his vengeful ex partner in crime, in order to save the family he abandoned.

I think the premise could be an intriguing one... but I think it's vague at the moment as to what's happening and why:

• How did he discover he has a son? ? Is the peril because the ex-partner has discovered he has a son?
• Why is he exiled?
• Is he saving the son or the abandoned family (or both)? ?If he abandoned the family previously, why is he bothered about them - or has the son given him a new viewpoint?

To me, the inciting incident is not the discovery he has a son but the discovery that his vengeful partner is after his family. That's what sets up the goal of saving them. The discovery of the son is actually irrelevant as it stands. However, if the vengeful ex-partner kidnapped the son he didn't know he had it would tie in more. The fact he didn't know he had a son though is still somewhat superfluous. It doesn't change the desire to save him.

Exiled? Exiled from what? The gang? The country?

Why is the ex-partner after him? If he's kicked him out of the gang why punish him further?

What's the protagonist's arc?

Definitely think there's potential, I think we just need a bit more info and all the details to mesh together.

Hope this helps.