Property Dispute

Hellow sir, I am having a dispute with my brother in law with respect to property he is not providing a share in property I am sharing the detail about the property here: 1. The notary of the land is on my grandfather's name and he is no more 2. There is no registry of the concerned property on anybody's name in my family 3. The person who sold his property to my grandfather had also passed away. 4. My brother in law is carrying on the construction work on the concerned land Actually I am in a doubt that is the construction work completed whether I would be able to claim on that land or not also either I can stop the construction work legally by taking sheriff's help. If I can't claim on the property wether I would be able to sue against him and it will go in government hand and the government put a stay on the construction or sell that land buy helding auction. I am in a great trouble and seeking for your further I would be grateful to you if you help me with this matter thank you for giving concern to my matter