my grandfather and his cousin was having a joint residential property in bihar. both have died. after that my grandfather 50% portion had transferred to my grandmother according to documentary proof.my grandmother has died and she has three sons alive. two sons have sold their portion to my father under registry. so my father is the only owner of the half portion of the property. on the other side my grandfather cousin died and his wife has also died. now according to the documentary proof half portion of that property is in name of her two sons.again they have filed title(partition ) suit and before that they have filed case under 107 for contempt of peace in which my name has also been involved. i m a goverment servant and residing in delhi and at the time of filing the case i was not in delhi. i want to know that can my father sell that half portion of the property and what can i do in delhi against those. my parents are old aged.