You can open a VB6 .vbp project file in Visual Studio. This automatically invokes the project converter, it will try to translate your VB6 code into VB.NET. The translator does a fairly decent job of it but the VB.NET language has changed pretty drastically. It depends on how 'clean' your VB6 code was.
After the conversion is completed, you'll have to walk through the list of warnings and errors you'll get. Getting none at all is rare. There might be hundreds or thousands. If you're in that boat, it starts making sense to rewrite the code.
Anyhoo, just try and see what hits the fan. You'll have a good idea what you're in for in about ten minutes. Don't forget to copy the project before you start the conversion.