No, sorry. That's a hopeless case. PM 6.5 didn't even run on Win Vista. All you can do is try to somehow create a virtual machine with a full WinXP and use that.
InDesign used to be able to open Pagemaker files. I don't know if the latest version still can.
It was never 100% accurate and it was best to prepare the files in Pagemaker first to get the best results which, of course, you can't do.
You could download a demo copy of InDesign and give it a try. It won't cost anything and it will at least tell you if it works.
If you are talking of a large number of files, I woul say that your best bet is to get an old second hand computer with XP and keep it for working in PM. A portabler one should be very cheap and takes very little space when not in use.
Get an WinXP PC if you wish to continue using PM6.5.
For PM 6.5 I’d go back to Win98.