I've noticed that when I use yogurt when I'm making Indian flatbreads they seem to roll out easier, compared to when using just water or milk. So maybe the acid breaks down some of the gluten, making it easier to roll out out. Why didn't you use the yogurt? If it's a problem with dairy, you could add a small amount of white vinegar, or some citric acid, to make up for the acid.
I hadn't seen parota bread before, so I googled it, and it bumps me to paratha bread. So is it this Indian bread you are talking about? And the atta flour they call for, but you aren't using? If so, that's a ww flour made from durum wheat, which, even though it has a lot of gluten, is easier to roll out. If you can't find it, maybe substitute some pure starch, in place of some of the flour - a trick used for making "cake flour" is to add 2 tb cornstarch to a measuring cup, and use that to measure the all purpose flour with. Still, if it's atta flour you are trying to substitute, try some WW, maybe with the starch added, or WW pastry flour (though around here, atta is easier to find than this!).