What does Hontou ka Watashi wakarimasenka Sou desu ne mean in English?

[I'm only learning myself, so I'm sorry if this is wrong.]

To the best of my understanding, there's essentially 4 compontents to this:

Honto ka \ Watashi \ wakarimasen ka \ Sou desu ne.

Honto ka: Really?
Watashi: I [formal]
Wakarimasen ka: I don't understand? / I'm not sure?
Sou desu ne: Let me see.

So, as a literal translation:

Really? I don't understand, let me see.

Hope this helps.