Reshape / Transform an upper triangular matrix in MATLAB

Reshape / Transform an upper triangular matrix in MATLAB

I have an upper triangular matrix (without the diagonal) given by:
M = [0 3 2 2 0 0; 0 0 8 6 3 2; 0 0 0 3 2 1; 0 0 0 0 2 1; 0 0 0 0 0 0]
The resulting matrix should look like this:
R = [0 0 0 0 0 0; 0 2 0 0 0 0; 2 3 1 0 0 0; 2 6 2 1 0 0; 3 8 3 2 0 0]
Since I couldn't find a simple explanation which describes my goal I tried
to visualize it with an image:

I already tried lots of different combinations of rot90, transpose, flipud
etc., but I could't find the right transformation that gives me the matrix
R
EDIT:
The rows of the matrix M are not always sorted as in the example above.
For another matrix M_2:
M_2 = [0 2 3 1 0 0; 0 0 3 6 3 9; 0 0 0 1 2 4; 0 0 0 0 2 6; 0 0 0 0 0 0]
the resulting matrix R_2 need to be the following:
R_2 = [0 0 0 0 0 0; 0 9 0 0 0 0; 1 3 4 0 0 0; 3 6 2 6 0 0; 2 3 1 2 0 0]
Again the visualization below: