Can I the Son have right on my Alive mothers inherited property

My Alive mother approx 70 Years old,has inherited 1 acres( 3 Bigha) of agricultural Land from my Late Maternal Grand father. This was done by a Dan Patra made by my Maternal Uncle. Presently She she came under the influence of my married sister and Brother in Law.And telling She will either sell the property and the money she will give to my sister, or she is telling to give 30-40% of the land to me. I requested several times to give equally to both of us. But She is not agreed. My sister and father is also not agreed on me,as I have a little more capacity of earning than my Brother In Law. And I objected to sell the property as once the property will go out of our hand we can not purchase again. I have even told to my Mother to keep the Land as it is. And she said: she wants to help my sister in constructing their house by giving money to them( by selling the Land). I got disagree. I want to know: As a Son do I have any right to my Mother's Property which she got from Her Father through Inheritation. My Question: If she got the property by inheritance, how do she deny my inheritance on it.