An employee has two contracts with the same company. Which one is correct?

Good afternoon,

I have a question.

I have an unlimited employment contract with a company in RAKEZ Free Zone. In this employment contract, it states that I have a 6- months probation period with 1-day notice during the probation.

Then, I have another employment contract from the company and it states a different probation period (3 months). Which contract is legally the correct one? And when I resign (I am in my 5th month now), can I use the 1 day notice period?

Thank you so much for your help!