Post metod to a VIP which has HTTP_TO HTTPS redirect irule

HTTP protocol does not have a redirect for POST method. You can achieve what you're looking for with HTTP respond 307 status redirect (repeat POST request to a new location). Note that Web Browsers will prompt the user to confirm such redirects. By design, its not meant to work the same as GET redirects due to security constraints. Personally, I see POST 307 redirect as a last-resort workaround which is acceptable for internal-use-only corporate tools. In case of client-facing apps, I would not recommend it. Such security-related prompts at your web-site won't contribute to positive customer experience.