• Claiming adverse possession in property in Mumbai

We r staying in a property in mumbai which was a open plot since 1975.the area is 3500 square feet. the landlord made tenant agreement without mentioning the lease period in it. Till wen agreement getting over or which year ending never mentioned. The agreement does not have stamp paper, both parties only signature is there. Not even once he came to collect rent. The rent was never asked he also never showed up. It was a khadi land or pond type with dirty water on that land. We put about 150 trucks of sand to level it. We made houses there planted trees put fencing and compound wall now. Till now we r on possession without any trouble. . The landlord passed away. His son became the owner. He sold the property to someone else in 2016.the new owners have sent a trespasser suit in civil court against us in April 2017. The new owners r after the property now. Now how to we defend our land or claim it. Can we claim adverse possession of that property. Or we have to fight as tenants or lease tenancy. Thanks Ravi