In this paper, we consider the information system  and the corresponding rough lattice  where D is the Praba join and Ñ is the Praba meet. We define the maximal and a minimal element of this lattice and prove its existence, also we define the complement of the elements in T. The complement of an element  for  is established. These concepts are illustrated through examples.

information system, roughset, poset, least upper bound, greatest lower bound, lattice, Boolean algebra.