Legal Partition of Intestate Father's property

Hi sir, I am a retired Army person currently working in a different role under the central Government. I have one Elder Brother and a mother both are living in the Village near Vellore, where my father had got a share of Agricultural Land and Residental Plots as a share of his father's property. I am currently settled in Chennai due to work convenience. My father died when I am 5 years old and my mother took care of my elder brother and me until I got a job in Army in 1985. I and my brother jointly built a house on the Residental Plots where my father got as a share from his father in 1988. After that, I got married in 1996 then after 2 years, I moved to Chennai because of work convenience. Till that, I was giving my complete salary to my mother and she used to give it to his elder son(Since he doesn't have a standard Job). So, from 1998 to till now My Elder Brother was enjoying all the Agricultural Lands and the House that we build Jointly. I also financially helped my mother and my elder brother when in need even after retiring from Army. My elder brother has 3 daughters I financially helped my brother with his daughter's marriage. Till now, I never received anything which is grown in our Agricultural Land. Recently, few months before I went to my Village to claim my share in the property which is in the name of my father. (House, I am not sure whether it is in the name of my father or my mother). But, Brother is not willing to give me my share so that he wants to divide the property in favour of his convenience by asking for a 15 feet common roadway to reach his partition Land. But the Land is barely 1.2 acre and the road itself will consume some 20 cents. My mother is 85 years old, my elder brother is Blackmailing her to ask her share in the property so that he can take her share in the form of will. Also, for the House, they are telling me not to enter the main entrance and make a new entrance with my expense to enter the House which is not practical Since the House is very old and could not tolerate any Alterations. (House was 27*70 (width*length) in dimension, He is asking for 17 feet(width) and he is telling me that he will give me only 10 feet(width)). My doubt is, 1. Whether I can demand an equal share i.e. 1/2 of the total area available in my father property (Land and House)? 2. My mother is asking for a share, Whether can I settle an amount and get a release deed from her? 3. Even if I got a release deed whether she can give her share to her elder son as per her desire before she dies? 4. If I file a case requesting for partition whether it will get partitioned as 3 parts (i.e. one part to my mother? 5. How to safely partition our Land so that my mother couldn't give her share to his elder brother? 6. Whether I can get a stay order so that my brother partition the Land as per my demand? Thanks for calmly reading my entire Question, Please advise the correct solution so that I get my Right share.