Can I claim property as per family arrangement

My grandmother purchased a property in1959. She has two sons and three daughters. They all constructed a building in a joint family income and some portion leased to tenets.But due to some dispute my grandmother wrote a will to his grandchild ( second son's son for me he is brother) in 1994. My father (elder brother of grandmother)filed a suit that he had rights in property and court ordered favour to my father's claim in 1995. My grandmother went for appeal in 1995 to dismiss the suit made by my father by claiming that she has right to write a will to anyone by claiming she brought and construt the property on her own. My grandmother died during a appeal in 2007 so my brother ( my father yonger brother's son that my grandmother made will) appeal to court as a petitioner to dismiss the suit. The higher court accept the petition and dismissed the suit in 23.08.2008 by telling that she has right to wrote will anyone.But in the mean time a panchayat is held in family and made a aggreement in white paper that we divide share and also withdraw all pending case in court which is made by my father on 15.08.2008. My father didnot mentioned about this family arrangement in court and High court is dismissed the original suit.After 2009 my brother made mutation in property and paying house and water tax in his name.my father died in 2019.since we are residing till now in the suit property.In 2019 he sent a legal notice to us by vacate and surrender the property to him and also filed a suit in court. Can I claim property by written document which is made in panchayat as we had share as written and signed in paper.Is it consider valid proof for claiming back our share in eye of court. PS: Written document were signed by all legal heirs of grand mother ( two sons and three daughters), me and also my brother (who is claiming property now) and also some witnesses.