Property Title Transfer On The Basis Of Family Settlement

Respected Lawyers, myself "N". I lost my father, a few days back due to Covid-19. We are Jain (by caste). Back in 2004-05, we had our family settlement between, five brothers including my father. As the settlement was done with mutual understanding between family members, it was done on Rs 100 stamp paper, but it was neither notarised nor registered. My father got a small agricultural plot, which was in the name of his cousins. As my father started approaching his cousins for title transfer according to the family settlement, they started making excuses every time. Everybody got their share cleared via title transfer and documents, but my father remains alone asking for his share, which to date has not been transferred to his name. Was my father in the wrong direction. Now, we want to claim it and transfer it to my mother's name. I'm here for getting legal advice from the best.