Can we undo a partition which is done unfairly?

We are 4 brothers are 3 sisters. After the demise of our father our sisters had gifted their share of land to all of us. Now we brothers wanted the partition of our share equally at all locations. Our eldest brother had passed away 15 years ago. So we are three brothers now. The children of our eldest brother had sold 80% of their share. They had their possession at all 6 location. We 3 brothers had a mutual understanding that we'll use the combined share at each location for the agricultural use only and when partition will be made we will take our share at all locations equally. We had a mutual consent on this because we have our land facing on the National Highway and that land has five times more value than the land at other locations. We decide to have our different khewat by filing a partition suit. Our now-eldest(2nd number eldest) brother filed the suit and me and my elder brother(i am the youngest) had given our consent for that. We both had great trust on our brother that he'll make sure the equal distribution of land at all location and especially the land on National Highway. After that we had signed just 2 times on the blank paper at home which are shown as our presence during only 2 hearings out of 28. We never went to court or anywhere after that. The suit was filed in June 2015 and We kept asking our brother about the Khewat or partition he kept on saying that it is not done yet. In December 2017 he showed some suspicious activity and when we enquired about the case we came to know that partition was done in February 2017. Then we got the case file from records and it showed that "snand takseem, naksha, bayaan,jawab, intkaal" everything was done by Assistant Collector 1st grade and the land facing NH was entirely on His(2nd number eldest brother) name. He has become the owner of that land which has five times more value than others. Our eldest brother had already taken his share at that location long ago and that was sold by his children after his death. So bascially now we two younger brother are the person who have not gotten the land facing the NH and our now eldest brother has eaten our share at that particular place. We didnt have a clue till December. Now we dont know where to approach or where to appeal as it has been more than 11 months already since February 2017. Please suggest me if there is any way that we can get our land on road. Thank you.