The length of your probationary period is stipulated within your employment agreement (usually in section 1, right below the Start Date). We also have this information available on the OmniPlatform.
To view the duration of your probation on the OmniPlatform:
Click on the Personal details in the left-hand side menu, then select Profile.
Scroll down to the Employment details section.
Your Probationary period in months will be here.