I need to convert a csv file into a shapefile in a .Net 6 windows application. I am looking for some assemblies or source code that does to use in the application. Does FSE provide such assemblies or have source code that can use the does this?

If you have a licensed installation of FME, you can use the included .NET API for this.

You'll find the documentation under <FME>\\fmeobjects\\dotnet\\apidoc

There's also a sample application under <FME>\\fmeobjects\\samples\\CSharp

If, for some reason, you cannot find the files, make sure that the SDK was selected during installation of FME.