Business property rights denied

Dear sir My father and 3 uncles started a partnership firm in Kolkata. The firm has got land allotments from WB govt in Saltlake Sector V (Approx 5 cottah) and also in Kasba Industrial Estate (approx 4 cottah) in the name of the company. The Kasba land has a 3 storied building built. The sector V land is still vacant. Both were allotted during 1984-85. My father passed away in 2004, and my uncles didnt allow me to get into the business. They didnt settle my father's share giving different reasons. Now after all these years, we (me, my mother and sister) demanded a settlement for my father's portion in the business. My uncles handed us a balance sheet dated 2004 with a meagre amount of Rs. 3 lacs. When we denied that sum and demanded our share of the Sector V and Kasba estate lands, they informed us that since these lands are allotted by government to set up industries, there cannot be any valuation for these and hence we cannot demand any money from these properties. 1. I want to know if it is true or not? 2. Is there any way to get my father's due share claiming these properties. 3. What are the steps that we should follow? Kindly help. Thanks Deb