Partition not done by Uncle after my fathers death

My father's family and his brother's family were living jointly. Due to some minor clashes in the family, they decided to live separately. After that things were back to normal. However, my father and his brother(my uncle) were equal partners in the wholesale grain business which was founded by my Late. Grandfather. The shop is in rent since 30 years. My father was a little innocent and hence all the finances were managed by my uncle including major business decisions. My grandfather left few properties of land when he died. My father used to sign wherever my uncle asked him to. My Uncle managed all this property to stabilize the business. He sold all the property in my fathers name and later bought in his own name and his family members name. My father was left with only one piece of land in his name which my uncle did not sell because I could later build my own house there. But after few years, the property rate rose and he sold that too for a price of 90 lacs promising us that he would buy a house for us. We were waiting for that time to come but in vain. Three years back in 2012 my father died of heart attack. My Uncle took all the death certificates from me. I do not know how he managed to transfer the partnership of the office in my father's name to his wife's name. My Uncle also had the cheque book of my bank account which was blankly signed by me. He also had the debit card. He used to operate my account for years. My father had an LIC of around 1 lac and a PPF of around 1.5 lac, the nominee of which was my mother. He asked us to claim the money and we got the money and it was credited to my mom's bank account. He, later took the debit card of my mother's account. I went back to continue my IT job in another city. He took this amount of LIC and PPF from my mother's account without asking us. When we came to know we didn't say him anything as we believed him. We were in hope that he would settle the partition in the right way. But after a year of my father's death he started torturing my mother by not paying monthly expenses and asking to leave the city. Since things were going out of control, I brought my mother with me. Some time later(in 2013), my account was credited with 5 lac and 4.5 lac(Total 9.5 lac) which again my uncle took. Now he is not paying us a penny. I do not have any proof with me that he took this amount. However, I can make the bank statements available. We feel cheated. Our trust was betrayed. Now, my question is, it wise to pursue a legal action against him, if so how. How much legal cost will I have to spend in total and how much time will it take to settle this matter in the court? Is it beneficial? I have heard that legal path is quite long and involves lot of expenses. Moreover, I do not have much proof in hand to support my claim. I currently work in Bangalore and my hometown where this whole story happened is in Madurai. Thanks for your time in reading this.