In conclusion, for Windows 10 64-bit, you already have DirectX 11. To make it "better," update your operating system and graphics drivers. Avoid any website offering a standalone DirectX 11 installer – they are either obsolete or dangerous.
I understand you're looking for information on downloading DirectX 11 for Windows 10 64-bit, and you've used the word "BETTER" to emphasize quality or a specific version. However, it's important to clarify a common point of confusion: Directx 11 Windows 10 64 Bit Download BETTER