Father had two wives, what will be the children share from both wives

Sir, My Father has two families, both the wives are own sisters, First wife has son, he got married... To my mom, I'm the only daughter, first wife has house, & income source, but they didn't give us anything.... We are in rented house, no proper source for us, there are two plots outside the village, we are asking them to give those two plots for us but they are not, kindly tell us what to do.... What rights do I have on that property?