Ownership of property

Hi, Raj here, My father purchased land in 1993 by sale deed and pahanis mutated on his name. Other person s trying to interfere on property by fake sale deed that he sold to them in 1996. In between in 2008 he got paattadar passbook as he in pahani from year 1993 to till 2008. Same gifted to mother's name by registration. Actually 1995 it was disputed in court my father got injunction order for his sy number and others for their sy. Number. In meanwhile they threatened my father and stopped him to reach court, and suit was exparte decreed in their favour. Now mother filed suit for declaration, we submitted pahanis registration docs etc, other side they submitted fake sale deed etc. Can we win this case. Please advise. Thanks.