Fine. And as I said, a TProcess wants the name an ELF file.
A Javascript file is not an ELF file, it's text.
A shebang is not handled specially, it's text.
It might be fixable by asking a TProcess to run /usr/bin/env etc., or you might have to ask it to run the node binary (wherever it is) with a bit of fossicking around with explicitly provided shell (environment) variables, or you might just be able to do it by invoking a shell. That's your problem as a Javascript etc. user, not ours.
This is hardly the first time I've seen this sort of thing, in fact it might not even be the first time this week. I suspect that @TRon's sitting there giggling :-)
MarkMLl