My question is regarding salah;
That if I go to umrah or hajj, can I pray behind the man leading the prayers in Masjid al Nabawi or baitullah cause the person leading the prayer is a rejector of the wilayah of Ameer al momineen Imam Ali (asws)

You can stand in line with them and pray but you must recite al-Fatiha and the other surah for yourself