Inheritance split between siblings

Hi, I would like to ask advice on how should the split of inheritance between siblings be handled. The property is named after my deceased grandfather. It appears that he didn't prepare a last will and testament. My grandmother, his spouse, is still alive but not on a good mental state. Some of the siblings plans to sell the house and just split the profit but there are others that claims the property as their own. What are the legal actions that we should do in order to proceed with the selling of the property? Do we need all siblings to come to an agreement? Should it be equally divided or there are some considerations on how much each will get?

Your surviving spouse would have to get her conjugal share first, then the remaining portion would be distributed equally among their children (assuming that your grandfather has no illegitimate children). Assuming that your parent (child of your grandfather) is still living, then the share will pertain to him, and not to you and your siblings. But if your parent is no longer living, then his share (and only his share) will have to be distributed to you and your siblings equally (assuming also that your parent does not have any illegitimate children). https://www.alburovillanueva.com/wills-succession-inheritance This would be the rule if you and your siblings really cannot agree.

But if you can agree on how the property should be split up, then all the remaining heirs may execute a deed of extrajudicial settlement, stating the desired distribution among yourselves. This is only applicable if ALL of the remaining heirs can agree, because if not, then you have no other choice but to go to court and settle the estate judicially, which would include the subject property as among the assets that would be distributed.