Unfortunately, not a simple answer
..NET does not support the JVM. Everything in .NET is compiled to CLR and
then JIT'ed to machine code regardless of language.
..NET does support the Java *language* through J#. It also implements the
Java libraries but only up to version 1.1.4. Note that J# the language is
also only current as of 1.1.4.
So .NET is Java *source* compatible up to v1.1.4. You can take Java source
code and compile either under a Java compiler or J# compiler. However there
is no support in .NET for .class files, etc.
J# gives you access to the entire .NET framework as well as the Java 1.1.4
libraries.
Santiago