So this is how i finished it

((12),0)H={((12),0), ((23),2), ((13),1)}

((123),1)H={((123),1), ((132),0), ((123),2)}

((123),0)H={((123),0), ((132),2), ((123),1)}

((132),1)H= {((132),1), ((123), 0), ((123),1)

And so the left cosets would be

((12),1), ((23), 0), ((13), 2), ((12),2), ((23),1), ((13),0), ((12),0), ((23),2), ((13),1)

And the right cosets are

((123),1), ((132),0), ((123),2), ((123),0), ((132),2), ((132),1)

would this be right???