Allamah Suyuti (rahimahullah) has enumerated up to nine different verses or surahs of the noble Qur’an that were revealed more than once,
1. The last few verses of Surah Nahl
2. The first few verses of Surah Rum (Surah30)
3. Surah Fatihah (Surah1)
4. Verse113 of Surah Tawbah (Surah9)
5. Verse114 of Surah Hud (Surah11)
6. Verse85 of Surah Isra (Surah17)
7. The entire Surah Hud (Surah11)
8. The entire Surah Isra (Surah17)
9. The entire Surah Ikhlas (Surah112)
The scholars have documented various reasons for which a particular verses or an entire surah was revealed more than once. Some of those reasons are:
1. As a reminder.
2. Due to the recurrence of the need.
3. To illustrate the honor/significance of that verse.
4. Sometimes, the second revelation was in a different dialect.
(Al-Itqan fi ‘Ulum al-Qur’an of Allama Suyuti pgs.48-49)
And Allah Ta’ala Knows Best