Remove Duplicates Of Multiple Columns

I have searched the many forum solutions for duplicates however the ones I found relate to a single column. However what I would like to be able to do is starting from row 6 is to remove duplicates of multiples columns of a single worksheet, namely columns M, O, P, Q and R. Note some cells in each column are blank.

To clarify - it would firstly check for duplicates in column M, keeping just one of the rows of the duplicated value and removing entiely the row/rows of where the duplications appeared. Then go through each of the other four columns. of the worksheet doing the same for each of the other four columns.

Then after the duplicates are removed from all five columns provide a tally at the bottom of the worksheet of how many times a value now appears in the cells of each of repective columns.