Do we have any right ?

My grandfather rented a shop about 57 years ago with my father stilling running the shop for our livelihood ! The actual owner of the property has sold the whole property including the shop which we rented and of which we regularly pay rent which is nominal in accordance with the duration we are running it , to a third party ! The new party which has acquired the rights have deliberately demolished the property making it appear to be have fallen naturally ! Actually the shop is at ground floor and the two floors have above the shop have demolished right into the shop ! This has made the use of shop impossible! So there are few basic questions The landlord (new) is asking for rent about 100 times that of initial rent !!? Is it legal !?? Secondly can we repair it and run our business again smoothly !? Thirdly by any chance can we become owner ?? Or is the landlord liable to us in terms of money ?? Important note ! The shop is small but at prime spot and our daily livelihood depends on it ! Moreover the tenant my father is a senior citizen ! So what are the ways out ! Plz guide