Season 6 of Kuruluş Osman picks up from Season 5, with Osman Bey expanding his power by conquering Karadin Castle. Commander Lucas plots to divide Turkish lords using stolen sacred relics, while Alaeddin's fate remains uncertain after the siege. Orhan Bey proposes to Holofira, and Saruca and Yusuf compete for Fatma Hatun's affection. Meanwhile, Begüm accuses Hazal Hatun of poisoning her, adding more drama. Osman faces growing threats as he fights to solidify his rule and protect his people.