The numbers on the right shows the required total value of the row. The numbers on the bottom shows the required total value of the column.
The Roman numeral shows the value of each cell, relative to the total value of the row/column. If you’re focusing on a row, then only the horizontal cell values are relevant. Otherwise, only the vertical cell values are relevant when focusing on a column.
Sorry if I can’t explain any better, but you can also search up the tutorial of the puzzle. Was able to know how this type of puzzle works through Google. I forgot what the name of that puzzle is, but the name is shown vertically when doing that puzzle.