Rent not paid by tenant more than a year

  sir

  I had old house in my own town  my mother was resisding in that house. my mother was passed last year now the  house  is maintened by myself . two shop in that house its rented out  they runing the shop more than 30 year i aked for rent both them said that   we are in this permisses  more than 30 year before  you born will not  pay any rent to you and we ready to  face any  legal issue.   how to get  rent  or vacate them