Loop to check condition of cells

Hi,
I'm looking for assistance with some code that I've been working on but haven't been able to get it to work. Column R is a calculated cell that adds percentages across the worksheet. I would like to prevent the responders from having a percentage over 100% in column R. For example, the value in R6 is currently 100% but if the responder changed V6 to 10% then the "Grand Total" would be 105%, which I'd like to have an error message displayed when a cell R6 and below are over 100%.

There may be some additional rows added and I'd like to make sure that the code contains a variable to check every row in column R starting at row 6.

The code I've tried is below:

Please Login or Register  to view this content.

Please let me know if there's any additional details that you'd need to know. Thank you in advance for taking a look at this.