Grandson share and right over grandfather's Property

Sir/Madam, I am staying at C.R.Park , which is self acquired property by my deceased grandfather. It has two floors. On ground floor, my uncle , aunt, grandmother resides and on Ist Floor, I live. Ist Floor was built by my father in 1987. My father -mother were seperated in 2000. My father abandoned me and my sister in 2003 and since then is staying at Faridabad with his illegitimate family. He didnt divorce my mother and married a maid servant and is staying separately since 2003 .My Sister recently got married in 2015 . I am staying alone at First Floor C.R.Park. My questions are as follows :- 1. What are my rights at self acquired property of my deceased grandfather ? 2. Can my father ask me to go away from C.R.Park House and debarr me from all rights and stake over C.R.Park Property ? 3.Can my father's illegitimate family claim stake and share over my deceased grandfather's C.R. Park Property ?? Does my father's illegitimate children have stake , share, right to reside at my deceased grandfather's C.R.Park Property ?? 4. What are options , alternatives available for me ?? Regards Debjyoti