Is it valid for women to pray in congregation in a room separate from the Imam and the congregants?

It is permissible for the congregant to follow the Imam if they are both in the mosque, even if the congregant cannot see him or those behind him, provided he hears the takbir. This is because the mosque was built for congregational prayer, and everyone within it is considered to be in the place of the congregation. However, if the room is outside the mosque, it is permissible to follow the Imam if it is possible to know his state, even by hearing his takbirs. But if following him is not possible, the prayer is invalid and must be repeated.