Making Mooli Paratha's is a bit tricky as radish when grated tends to secrete water. If this water is not drained/squeezed properly, it will make the stuffing wet thus resulting in tearing your paratha while rolling it. So the trick is to squeeze out all the water really well and then add salt just before stuffing and rolling the paratha. Also, use enough wheat flour to roll the paratha to prevent them from sticking to the pin and tearing.