Civil suit filed against property sold 15 years back

Hi, I have purchased a land in Bangalore and registered it to my name on 14th August 1991. The brothers of the seller who sold the property, have filed a civil suit; they state that the seller and his brothers belong to joint family and had kept the land in the elder brothers name(seller). But the seller has sold the land without informing his brothers(total 3 brothers including seller). Now they have filed a civil suit on 3rd March 2007, claiming 2/3 of the share in the land against the seller and me. I have 3 questions: 1. Since the civil suit was filed after more than 15 years of selling the land, does it stand?(My advocate mentions that any civil suit filed after 15 years of selling the land will not stand in any circumstances) 2. The 3 brothers(including seller) have made a partition agreement among themselves, in which its mentioned the land in question is allotted to the elder brother(seller). I have taken the copy of this when I purchased the land, but it is not registered partition agreement. 3. I have been running an educational institution since the year 2007, now the 2 brothers have applied to the court to grant a stay order on the land. So that I dont alter the nature of the land. If the court grants stay order, i will not be able to expand the infrastructure of the school. Will court consider that an educational institution is being run on the land and dismiss the application filed for stay order grant?