I have been programming in RmCobol for many years. But I am using Version 5, 32 bits. It is a problem for me now, I need a compiler with runtime compatible that can runs in 64 bits, no matter how old is. Any help will be appreciated.

Because RM/COBOL compiles to a machine-independent (or virtual machine) object code, 32- and 64-bit does not apply to the compiled object programs.  (This is similar to Java byte code, which targets a Java virtual machine.)

Both RM/COBOL Compiler and Runtime come in 64-bit versions for modern platforms.  (DOS is definitely not a modern platform.  Windows, perhaps?)

The good news is that RM/COBOL maintains backward compatibility for object programs compiled with older versions of the compiler.  This is documented extensively in RM/COBOL User's Guide, Appendix H, Object Versions.  

So, you should be able to license a runtime for a modern platform and run your application without recompilation.  (Especially good if you, like many folks with older applications, might not have the exact source code.)

What specific issue are you having that caused you to post this question?

I have programs in Rm Cobol 85, but the runtime does not work in 64 bits system.(Windows). I cant find a suitable runtime