Legally divided land selling problem

Is there any law or right to sell our land which is divided from our father's father land (which had been divide to him legally by his father (my great grand father)) what means while we trying to sell our land to some one they saying they will buy( they saying in future tense) , we are need in money for our sister's and my brother's marriage ( i mean money to give bride jewelry , etc ) they (my father's brother 's) had their land far way from us ( equally divided by elders ) they when we ask they saying we buy, they if we ask money urgently for this purpose. they saying we dont buy. but they not allowing others to buy. who wanting to buy (we ready to sell them) is our neighbor ( side filed fellow) can we put case in police station ? or is there any right them ? every thing is welly divided among brother qually and there is no well(water/ pipes ) and no borders problem. and it is in our father 's born village . just 5 km from us. my father is mentally ill' he can talk ,only my mother and my sister on our side. im last one in home we speak only Telugu. please sir can you say any solution to this problem. my mother crying so much because of this problem pls . thank you in advance sir, truly Anil kumar jammikunta Telangana INDIA.