Which one prevails in case of contradiction, offer letter or labour contract

I have a notice period of 90 days as per my offer letter, whereas as per my labour contract registered with JAFZA it is 30 days. Please let me know which one will prevail over the other.

I would also like to mention that it is specified in my offer letter that in case of conflict between the labour contract and the offer letter, the terms of the Company's offer letter will prevail.