Property succession in HUF

My grand father has three sons and two married daughters (one out of these two daughters passed away). They were married 45 years back. My grand father has both self acquired and ancestral property. Till today, he did not distributed any property to his sons. For the past seven or six years, he was inactive and unable to perform any financial matters. He lives with his younger son. Meanwhile this younger son took all the financial activities of my grand father into his hands and my grand father has no objection to this. Now his first son wants his share of property. But the younger son who took all the financial matters into his hands, along with his second brother and my grand father playing tricks and not giving proper share to the first son. Q1. What are the options available to the first son to get his share of property (both cash and properties which include agricultural land and houses) Q2. My grand mother is no more and she also has some agricultural land in her name. Will the two daughters get any share either in my grand father as well as grand mother's agricultural lands ? Q3. What are the rights of a grandson in the property of the grand father's self acquired or ancestral property, when the grand father is alive ?