I don't think it is the land. It still belongs to Devika or is in her possession and the Kapoor family is aware of the bad relationship bt her and her son-in-law. Why should they think that the land will come into Gauri's possession?
If it is the land, the Kapoors had the golden opportunity to get it when Gauri decided to divorce Shiv on Devika's saying. Two birds could have been got with one stone.....the land for the KApoors and freedom for Shiv and also he would have saved Gauri's life.
Why didn't shiv and his family go for it then?