How do I know which version of winscp I should download?

I have a custom application written 20+ years ago in original Visual Basic6 (NOT .NET) which send out reports.
Code is compiled on Windows XP.
It uses Mabry components for email and FTP.
We need to change to use SFTP (on very short notice) and it looks like WinSCP is the way to go.
I see there are multiple versions of WinSCP.
How do I know which version to download?
Any help would be greatly appreciated, especially that I'm under a very tight deadline.

Sorry, but that's quite vague question.
You didn't even tolds us, if you aim to use WinSCP scripting or WinSCP .NET assembly.
I guess you might want to use WinSCP scripting, so download the "Portable executables" package:
https://winscp.net/eng/downloads.php#stable_portablezip