What is my share in grandfather's property

what is my standing in our grandfathers property my grandfather had 2 wifes ,my father is the eldest son alive of his first wife ,and from his 2nd wife my granfather had 3 sons till before marrige my father wid my grandfather worked to build a factory and ahouse since the other brothers were very young after my fathers marrige things were not good at home regular family disputes led to the expulsion of my father from home and factory now granfather died about 8 yers back leaving a will with probably everything in his 2nd wifes name she is obvisly not interseted in being fair now we need our right and i need guideince on how to proceed with this and what provisions do we have in our law regarding such cases i m a sikh