What is the amount of time a will should be discussed and if there is no will when should all heirs be included in dividing up the property?

My gram passed in 12/2007. My aunt was appointed the executor. She has had no contact with her only sibling (my father) in regards to a will or having property split up. She originally told him after my gram passed that she had added both his and her name to the house deed. We've recently found out that the house is for sale without his knowledge. We checked the public records of the country and she lied, the house was only placed in her name. There has been a family riff in 2010 that has given her the excuse of not wanting contact with my father, however can she totally leave him out? We need to know what his rights are and if he can stop the sale of the house since he should have interest in it. Also, is there a time limit to when he can pursue his interest in his mother's estate? Must she disclose all financial information? Over the past 5 years they have been spending money freely and we believe part of those funds should have been my father's inheritance.