Shura (consultation) is a right for the Muslims alone and the non-Muslims do not have a right to it. It is permitted for all of the subjects to put forward opinions, whether Muslim or not.

The fact that Shura is a right for the Muslims is proven by the two verses

“And consult them in the matter.” (TMQ 3:159) and

“And whose affair is [determined by] consultation among themselves.” (TMQ 42:38) with respect to the Muslims, and His (swt) words

“So ask the people of the message if you do not know.” (TMQ 16:43) with respect to the non-Muslims. So Allah (swt) ordered the questioning of the People of the Book regarding whatever we do not know, and this is proof for the permissibility of taking their opinion, and if it is permissible to take their opinion it is permissible for them to be members of the Shura council.