Hello Kiruthiga Sundararaj, in order to get the M365 E5 developer subscription, you need to have one of the qualified Visual Studio subscription types, be a part of the ISV Success program or be part of the Microsoft AI Cloud Partner program. You can check the full list here -- https://learn.microsoft.com/en-us/office/developer-program/microsoft-365-developer-program-faq#who-qualifies-for-a-microsoft-365-e5-developer-subscription-
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