Is "Sana said that I would help you" correct?

Why

Kabir is treating faithfulness to Sana's exact words as the most important thing, which sounds respectful of what she actually said, but reported speech isn't a word-for-word recording — it's a description told from a DIFFERENT speaker's point of view. When Sana said "I", she meant herself; but when Kabir reports it, "I" in his own sentence would now wrongly refer to KABIR, not Sana, since pronouns always point to whoever is currently speaking. The pronouns have to shift to keep pointing at the right people from the new speaker's perspective: her "I" becomes "she" (Sana, from Kabir's outside view), and her "you" (meaning whoever she was talking to) becomes whatever fits that same person in Kabir's sentence. Test: imagine Kabir was the one Sana was talking to — Sana's "I will help you" becomes, in his own report, "Sana said that she would help me", both pronouns correctly repointed to match who is speaking now. No, the pronouns must change too: reported speech is told from a new speaker's viewpoint, so "I" and "you" have to shift to keep referring to the right people.