@fx.eko I don't think it will be as trivial as just putting your VB6 forms and modules into a converter and getting the resulting FPC source files. Free Pascal is a whole different programming language. Comparable to C/C++ but somewhat elegant in syntax and relatively safer due to lack of pointer arithmetic.
Threads like these will help you to migrate your projects, folks who have migrated apps from VB to Free Pascal often share their experiences on these forums. And even though migration might take some initial time and effort, it is very much advisable especially in light of direction that Microsoft Desktop technologies like Windows OS are taking.
And remember, Free Pascal isn't the only option, there are dozen others like Swing, Tkinter, PySide/PyQt, etc. The advantage of FOSS is that even if you switch to a Linux or MacOS desktop tomorrow, your application and code would still remain portable and thus you will future-proof yourself.