No, it means the stitch patterns will have 6 or 2 sts in them. For example, the granite st is a multiple of 2 sts because on one row you k1, p1 - repeated across the row. The basket st is a multiple of 6 because you k3 p3 across the row then later switch to p3, k3 across the row. So 18 sts is a multiple of 6 because you can repeat the st pattern 3 times; it's also a multiple of 2 because you can repeat that st pattern 9 times.
sue- knitting heretic