Microsoft no longer supports VB6 development and support from Microsoft has already stopped. But VB6 applications still run on Windows 8.1. See also this article titled "Support Statement for Visual Basic 6.0 on Windows Vista, Windows Server 2008, Windows 7, Windows 8 and Windows 8.1".
When would a VB6 application stop running on Windows? Is there any official statement from Microsoft or any clue about the same?
EDIT: In this link, the Visual Studio team has mentioned that, "It will be supported at least through 2024". But it's not clear whether they said it's supported in Windows 8 till 2024 or in future release of windows OS too.
The "2024" means as part of Windows 8. The link says the VB6 runtime is part of Windows and therefore will be supported in the same way as the rest of Windows. For example Windows 8 will be supported until 2024 because that's the support lifecycle for Windows 8.
EDIT: Microsoft have now said the VB6 runtime is officially part of Windows 10 too.
EDIT: the VB6 IDE (not runtime) is no longer officially supported on any version of Windows, but there are ways to get it to work on Windows 7 and 8.