Hi Raoul, I'm sorry, but there is no support for Cyrillic (or CJK or ...) in the current texinfo.tex. Although there is a long-term plan to support all this via LaTeX, that doesn't help you now. I fear that right now there is no good option.
You could try converting to Docbook and see if the Docbook tools can process it into PDF (I don't know what they are). Or convert into (Texinfo)XML and use texi2latex (an independent program, http://www.nongnu.org/texi2latex/), but unfortunately I suspect neither the 4.13 XML output nor that program are ready to do the job out of the box. Sorry, Karl
