I am trying to use index list to sort out integers that appear most on the list

So I created a file that compares a list of random integers and get number of occurrences of the same integers in the list and the unique individual integers.

I'm also trying to figure out how to extract only the most occurred numbers from the list, in this case would be 1 and 2.

I am trying to use the item index list but I can't figure out how to get the right index number for it to extract from the list. It has to work with any list of random numbers other than the one I have here.