flashing issue

Hi i have tried flashing different motorola phones using rsd lite with and xml firmware. I now have 2 motorolas one is xt1068 and other one is 1072. I have susscufully flashed xt1068 with 6.0 but when i flashed xt1072 it failed. I thought its firmware issue so i changed firmware and used tesco retail 5.02 gb it failed again at flash partition. I just want to know how to know what file we should use for the phone thanks