The Aramaic word for "finished" is "qṭal" (pronounced as "k'tal"). However, the exact phrasing used by Jesus is a matter of debate among scholars. Some believe he said "qṭal", while others argue he said "ślam" (pronounced as "sh'lam"), which means "finished" or "completed" but also carries the connotation of "peace" or "salvation."
Ultimately, the exact translation is subject to interpretation and depends on the specific context and theological interpretation.