In the paper, we extend known results concerning crossing numbers for join of graphs of order six. We give the crossing number of the join product , where the graph
consists of two leaves incident with two opposite vertices of one
-cycle, and
consists on
isolated vertices. The proof is done with the~help of software that generates all cyclic permutations for a given number
, and creates a~new graph
for a~calculating the distances between all
vertices of the graph. Finally, by adding new edges to the graph
, we are able to obtain the crossing number of the join product with the discrete graph
for two other graphs. The methods used in the paper are new, and they are based on combinatorial properties of cyclic permutations.