How can I retrieve my part of the Will?

My grandmother has passed away and has a Will that the four of her remaining children have shared upon each other. She had a total of 6 children but 2 have Passed away. My mother is one of those two that has passed. I found out that my mothers name is mentioned in that Will but have not been told anything about it by her remaining children. I do not know what the Will says exactly but if my mother is not present do one of her children have a rite to represent her? Do we have a rite to read the Will? One of her eldest children is in power of the whole situation and is not willing to share any information.