Family Settlement Deed Worth

Hi all There is one parental property in Delhi, which was in the name of my GrandFather. However after his death in 2010, it was transferred in the name of Grand Mother, where 3 sons and 1 daughter signed relinquishment deed in the name of Grand Mother, and now the file is in DDA office to get it freehold. And she registered the WILL as well in which it was clearly written that the property will be divided equally among 3 sons, and jewellery will be given to the daughter. All 3 sons live there and even i was staying there since my birth. However in 2015, my father expired and they all tortured us to go out of the house. After 6 months we shifted to another place and lock our rooms. Now the 2 sons and grandmother are calling, again and again, to vacate the rooms as it has to be used by another son and verbally saying that terrace is yours. Questions: Q1. So to get it in our name, is family settlement deed worth it? Q2. If we get it signed and grandmother gave another will or sign another family deed than what will happen? Q3. If grandmother refuses to sign the family settlement, then what can be the next step we can do to take our share? Please provide some valuable answers to get out of this.