slim, there are three Hebrew online bibles in the JW library. They are New World Translation of Scripture, Torah and Prophets Written in Contemporary Hebrew and the Traditional Bible. I think both the New World Translation of Scripture and Torah and Prophets Written in Contemporary Hebrew are JW publications and they render the tetragrammaton as (יְהֹוָה) which is pronounced Yehova so I imagine that is how they read it.
Most Jews simply read adonai (Lord) whenever they come across the tetragrammaton. Perhaps Kaleb could tell us whether secular Jews pronounce it.