Ancestral property received as per deed from grand mom to my mom

My name is Lakshmi, 27, married and living in Dubai. let me go straight into my question in a hope someone will help me out. After the death of my Grand father his ancestral properties transferred to grandmother and she raised a deed which says "this deed will be valid after her death" and divided the properties among her 5 children including my mom. My mother is suffering from arthritis and bedridden more than 10 years. As a side effect of the regular use of sleeping pills more than past 10 year's she is little mentally unstable in taking decisions. now my mother and Grandmother wants to sell one of the property. we are not against the sale of her property but her conditions are quite weird. She wants to deposit the money in her name and her mother's, due to her bad health and Mental condition she trust's her side family than my dad and us. Mothers family side was enjoying the full income from Rubber plantation on the property and since my dad was working abroad we weren't bothered about the income they looted. we are sure the money she gets from the sale will be again looted by my uncle and aunts by convincing my mother. since her mental situation is not stable we tried to convince her to put money in her name and in the name of my brother and mine. we are ready to provide an assurance that we will not withdraw the money without her concern. if we deposit's the money in our 90 years old Grand mother's name as per my mother's wish the problem is my Grand mother is only willing to name my uncle as the nominee. which means we will not have any hold on the deposit after the death of my Grand mother. My questions are: 1. can i claim for my share? 2. is their any way that i can block my mom and her family from selling the property. 3. can she sell the property without our concern? By the way,there is a history of divorce case filled by my parents and later withdrawn mutually will that affect anyway? Mom is bit aggressive and stubborn in nature because of her mental condition so she may opt to file again divorce if that may help her anyway in the sale of property. we can expect anything from her side to sell the property. please suggest me any solution to the situation. regards Lakshmi