Hello subrat kumar sahu,
Thanks for your question.
I will recommend you use .NET *8, as the specific wording from the retirement is "On 12 November 2024, support for .NET 6 in Azure Functions will end. Your apps that are hosted on Functions will continue to run, but security updates will no longer be available, and we'll no longer provide customer service for .NET 6"
Retirement: Support for .NET 6 ends on 12 November 2024—upgrade your Azure Functions apps to .NET 8
This means since you have not started it is better to use .NET8 for longer supportability an d for security updates.
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Regards,
Abiola