My younger brothers cheating me for property

I am eldest in my family and started earning since my childhood to give my family a good life and built property in the name of my father. Now my father is no more and my younger brothers faught and divided the property. We are total 4 brothers so the property divided in each one of them but very smartly they gave me the property which was not registered properly. As i am not educated and my children were too young to know about these things they took advantage of it and when I came to know that the property which I have received is not registered so i had to once again but that property which means indirectly i did not get any share from divided property. But they promised to contribute in the amount which we had to pay for registration which goes almost 1lac per head. But now they are denying and also some more property was there on which they are putting a false complaint that my father said that I should not be getting any share from it. Whatever I could I did for my father and my younger brothers and could not do much for my children. I am really not able to understand what to do kindly help. Its been almost 8 yrs now and they are cheating with me. Recently I explained my elder son about this which we were hiding from him has now asked to seek help from law. Kindly help what should I do in such a situation.