The most powerful dua for success in exam results is from Surah Taha. Here it is:

قَالَ رَبِّ ٱشۡرَحۡ لِي صَدۡرِي وَيَسِّرۡ لِيٓ أَمۡرِي وَٱحۡلُلۡ عُقۡدَةًۭ مِّن لِّسَانِي يَفۡقَهُواْ قَوۡلِي

Qaala Rabbi Ishrah Lii Sadrii, Wa Yassir Lii Amrii, Wahlul 'Uqdatam Millisaani, Yafqahuu Qawlii.

Recite this dua frequently during your exam days and continue to recite it regularly until the results are announced.

I prepared the whole year and studied well for my exams. I have already taken my exam, but I think I will fail. I forgot things during my exam. What should I do? Will this dua help me succeed in my exams results?