First up, any is an ADJECTIVE. It describes things. More specifically, it refers to one of something or several of something.
So you can say, "Is there any way to do this?", and you can say, "Are there any ways to do this?"In other words,
"ANY" DOES NOT NECESSARILY IMPLY SINGULARITY.
You can consequently say "if any of you IS available..." as confidently as you would say "if any of you ARE available". In the former instance, you are asking whether there is one person available. In the second, you are asking whether several people are available.

