A Tenancy Agreement protects both the landlords and tenants whereby there are terms and conditions that both parties must abide to during the rental period. This is to prevent any disputes from both parties.
In the event of non-renewal, under this clause either parties will have to inform each other so that the necessary arrangements can be made. This is usually done 2 months before the contract ends.
You will find our Tenancy Agreement guide here useful: https://www.propertyguru.com.sg/property-guides/tenancy-agreement-security-deposit-utility-deposit-in-singapore-9515
Hope this answers your question.