remedies for compensation or stay

i have constructed a house on govt land which is given by govt to me as a bhakhra visthapit but on record it's in the name of ho government but adverse possession by me..now the rail line is going in this land so railway authority has issued me a notice for dismantle my house without any compensation.. my adverse possession is from last 40 yearsso I have..to save it or for compensation to rehabilitation..