Two patterns are alternatively followed by the given figures,

Pattern 1:The elements in the upper triangle (P,Q,R in figure 1) or the ones in lower triangle(P,N,3 in figure 3) are shifted diagonally. The elements in the diagonal are shifted by 1 position with the elements moving in the North-West direction.

Pattern 2: The middle element is replaced by a new element.

For the formation of figure 6, pattern 1 is to be applied on figure 5. The figure thus formed is option B.