inheritance rights in property of a muslim women who married Christian even though he is married.

you first file petition that declaring that the christian man as husband and he was more than 7 years unheard and declaring the property to her. 

where are you from ?

Case / dispute involve multiple issues, which require professional consultation.

Living together from 2000 to 2012 certainly gives her the status of a wife, and it appears that the first wife is not interested not only in the land but her former husband. The Indian Succession Act of 1925 is a secular laws and Muslim in India does not have the proper laws like the Hindu  Succession Act. Now, it is seven years since he has disappear, in other words it is not known whether he is dead or alive. I suggest that you obtain death certificate of your husband and if you obtain his death certificate you file declaratory suit in the court as the rightful heirs to the land. Do not worry whether he is alive or death, just go ahead and if any one objects to your legal actions let them prove that he is alive, and you know what to do if he is alive. All the best.

"Christian man seems to be disappears no contact with him now the land which bought in his name at the time of living is still there with no possession now the problem is how to register those land ..................."

The facts posted are disjointed and the author himself is unsure of the facts. As such, no menaingful suggestion is possible.