My grandmother had custody of me,she passed , no will , could I be considered a heir of her estate.

Unless your parent, who was her child, died, you are not an heir.  However, there is a principle called virtual or equitable adoption that may cover you.  It is probably a long shot, but might be worth pursuing.  Of course, your aunts and uncles could all include you as an heir and give you a part of their inheritance.  You really need to speak to a probate lawyer with experience handling cases like yours.