@Sai Abhilash Thank you for reaching out to us, As I understand you have question on the dates regarding the migration of Authentication methods policy.
In March 2023 We announced the retirement date of September 30th, 2024 for managing authentication methods in the legacy MFA (per-user) and SSPR policies. We have extended the same to September 30th, 2025.
Same has been documented here - https://learn.microsoft.com/en-us/entra/identity/authentication/concept-authentication-methods-manage#legacy-mfa-and-sspr-policies
Let me know if you have any further questions, feel free to post back.
Please remember to "Accept Answer" if answer helped, so that others in the community facing similar issues can easily find the solution.