Generally speaking, all children have equal rights to the parental properties. So, under normal circumstances, all children and (in case of death of any child) children of the deceased one would have rights on the properties of parents.
But in the present case, ''some properties'' and ''release of rights'' create many more possibilities. What is meant by some properties? What about other properties of your mother? What is 'release of rights' before 13 years'? Why after 13 long years does your brother start a litigation? Answers to these questions require more details/information. In absence of additional information, the question can't be answered at this stage.
Beware! I question everything and everybody.