Jamal,
You are likely going to have to test each transformation against known control to better gauge which is the correction transformation. I am not familiar with your coordinate system, real-time network, etc. so I cannot help there.
If you are using Zeno Office/Zeno Office on ArcGIS and Zeno Field, your transformations are setup in your Survey Dataset/Survey Project. the coordinate system tab you highlighted in Zeno Field is only for the geoid model, which is applied in the Survey Project along with a transformation, if needed. If you are using Zeno Connect with Esri ArcPad, then the transformation is handheld in Zeno Connect. Note that ArcPad and Zeno Field are similar applications, but Leica's Zeno Field enables advantages to high-accuracy field data collection.
Mountpoints are defined by the real-time network provider. Each mountpoint is a unique product and you must select one compatible with your GNSS hardware. RTCM is utilized by most, if not all, GNSS equipment, including Leica. If you are receiving a phase-fixed solution and roughly 1cm accuracy, your parameters are set correctly for your real-time network. From there, it is based on the coordinate systems and transformations being applied.