Registered will

Mr chacko at the age of 71 is said to have created a will in favour of his son Mr Joseph, Mr chacko had three daughters apart from his son Mr Joseph, they are respectively Ms Marykutty Ms Rebecca and Ms Rosily. The will date as per certified copy is 22/05/1980 , at that time the eldest Ms Marykutty was given in marriage, and Mr chacko clearly spelled he has no intention to give anything regarding Ms Rebecca and Ms Rosily were unmarried, and by will the responsibility of giving in marriage of his unmarried daughter's is directed to the beneficiary Mr Joseph. Mr chacko died on 17/10/1980 just after 5 months after creating the will, in between this Ms Rebecca got married in August 1980 and Mr Joseph got married in September 1980. Ms Rosily got married late in April 1983.Mr Chacko's wife Ms Philomina had life interest as per certified will, she died on 11/11/2015, before the death ofrom Ms Philomina the beneficiary Mr Joseph had demised on 10/03/2010. As per certified the witness are two people the first is second daughter of testator Ms Rebecca and second is Mr late T A Rajappan (the advocate ) , now the said property is said to be sold by the spouse of the beneficiary Ms Sheeba, she is said to have a will in her favour by her late husband Mr Joseph died of cancer in 2010.But it seems there is no original will, Ms Rebecca the witness says her father was a kidney patient and was not having good sense to create, she has signed this document as insisted by her brother and beneficiary late Mr Joseph. When questioned about the sale of property she was adamant to give any reply. What should be the next course to claim our rights in the property. Kindly advice