RIS file are special ASCII text files that contain citation references. You can use text from any source (.txt, .pdf, .doc, .docx documents from Microsoft Word etc.) and simply copy and paste (or import if possible) relevant text data to a program that can generate RIS citations, like the Reference Manager from Thomson Reuters or similar programs.
Unfortunately, we do not know about any program that would be designed specially for word to ris conversion.Open WORD file Open RIS file
Bibliographic reference and citation management software