Denial of Mutation of Land Partition by Tehsildaar

Dear experts need your advice on the following matter: After the death of my grand mother our paternal land is transferred between two brothers (my father and my uncle). The land mutation has been changed and now its on the combined name of my father and my uncle. Additionally a mutual agreement has been submitted to the tehsildaar of our area that both the brothers has mutually divided the land among themselves. Before completing any other process of land division my uncle has constructed a elementary school on their portion of the land, without taking any approval from municipal corporation of conversion of the land from agriculture to commercial. As of now the land title is agriculture. My uncle had some financial problems and to overcome this he has sold 400 yards to some other party but because of joint ownership my father also signed on the document but it was clearly mentioned that my uncle is selling from his portion of the land. Now we want proper land division on the name of my father and my uncle but because of construction on my uncle's part of land the tehsildaar is refusing to do so and he has also issued a 90A notice to us. As my father got retired he started doing farming their and constructed a wall dividing land between my father and my uncle (total land size is 2 bigha, each one has 1 bigha in their portion). Now my uncle is applying for CBSE affiliation for his school but because of land rule he want to show our land as part of school's ground and for this without our knowledge he demolished a portion of dividing wall and removed my fathers name plate from the pocket of the land. I have two issue now, I know their is construction on the land but is their any way to get the land mutated on the names of both brothers, my uncle is forcing us to go for registration as tehsildaar is not agreeing to do the conversion. But local people are saying that even after registration of land (1/2 on my fathers name & 1/2 on my uncle's) will not serve the purpose and in the land database it will still remain a joint owned land of my father and my uncle. What should I do? Is registration is the right way or I should approach tehsildaar? But because of construction on land he is creating troubles for us. HOW CAN THE LAND LEGALLY PARTED ON THE NAMES OF MY FATHER AND MY UNCLE? AND IF MY UNCLE IS SHOWING OUR LAND AS A GROUND TO THEIR SCHOOL BASED ON SOME LEASE AGREEMENT WHICH MY FATHER HAS NOT SIGNED.