• Property Distribution if only Land bought on Grandmother's Name

We have a few lands which my father bought on my grandmother's name as he is the only son (and have two sisters). After buying my father gradually made houses on those lands in 20 - 30 years. Now due to some family problem, my grandmother went to live with her daughters for a week whom we suspect can play foul game for those properties ownings which is still in name of my grandmother although bought and made up by my father. My questions are:
1. If she will unfortunately die without a will, the whole property be divided into my father and her sisters equally?
2. This is not ancestral property as its bought by my father and is on the name of my grandmother, will it fall under law to be divided into all sons and daughters of my grandmother?
3. What is the best solution to get rid in this situation as my father doesn't want to lose his properties which he rose from nothing and made with his hard work in 20-30 years to the people who did nothing with it but may play foul game to eat their share? And my grandmother is being influenced by my father's in-laws who are taking complete advantage of our family problem to get properties from her.