`range()` and `index()` Count Differently

In the battleship game I have a big problem with the accuracy!
Range is using INDEX but the user know only about NUMBERS (for a normal person (2,3) means row 2 column 3 but here it means row 3 and column 4 cause we are using INDEX.
I tried to solve the problem with putting (-1) at the end of RANDINT but it does not work.
do you have any suggestion how to solve it?

given you are working inside a programming language, fiddling with range or indexes is a massive challenge. Manipulating user input is easier