CIVIL LAW - Inheritance of Family Property

Experts, please guide me in the following subect. In our family, I am the elder son (age. 53),and I have one younger sister (age. 48) and one younger brother (age. 45). My mother is alive. My father died in 1999. Our father had his ancestral property of 48 cent land and 52 cents of his own earning, totally 100 cents of land. Among these, father donated 10 cents of land to my sister as dowry, during her marriage. He made a will deed in 1996 stating that, the above mentioned property would be equally shared by both male members only, after his demise. At 2006, as per the will, we both male members made a partition deed, and keeping our shares under our custody with clear title. At present I have total area of 38 cents (14 cents of ancestral and 24 cents from father' s own earning) and my brother have 38 cents (10 cent of ancestral and 28 cents from father' s own earning). Now the problem is, my sister and brother have some dispute on their own ( not on property). In this instance, my sister wants to take revenge on our brother and is planning to file a case on our ancestral property through her son named Subash. Subash is promising me that he will return my share of the property, if he get the share from my property in the case. If so, it may be possible even after many generations. In this juncture, please advice me, the possible ways in which, I can safeguard my share property from being attached with the property case, which will be filed by son of my sister. Thanking you. By. S. Vijayakumar