I have made a script that google sheetwrites me the modification date of a specific range of cells and now I want to make it detect the cell that I am modifying and detect if it is within specific ranges.

This is the script I have:

function onEdit(HoraModificacion){
  var DateCol = "K9";
  var curDate = Utilities.formatDate(new Date(), "GMT+01:00", "hh:mm");
  var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Test2');
  var range = sheet.getRange('C11:K109');
  var rowIndex = range.getRowIndex();
  var colIndex = range.getColumnIndex();

  // May need to set up multiple ranges like this and check all ranges if
  // checked fields are not in adjacent cells
  var watchRange = { 
    top : 11,         // start row
    bottom : 109,     // end row
    left : 2,        // start col
    right : 12,        // end col
  };
  // Exit if we're out of range
  if (rowIndex < watchRange.top || rowIndex > watchRange.bottom) return;
  if (colIndex < watchRange.left || colIndex > watchRange.right) return;

  var currentValue = range.getValue();
  currentValue = currentValue.replace(/^\s+|\s+$/g,""); //"trim" kludge

  if (currentValue.length != 0){

    // Set a column to show last edit date
    SpreadsheetApp.getActiveSheet().getRange(DateCol).setValue(curDate);

  };
}

The problem is that I don't know how to make it detect the cell that I am modifying and from this detect in which range it is previously selected, I had thought of doing something like the one below, but it doesn't work out for me. The purpose of this is to have a series of controlled ranges, to know when they have been modified, each range has its own cell to write the modification date.

function onEdit(HoraModificacion){
    var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Test2');
    //Get the cell you are modifying to make a conditional for multiple range detect
    var activeCell = sheet.getActiveCell();
    //var activeRange = sheet.getActiveRange();
    var range1 = sheet.getRange('C11:K109');
    if ( activeCell == range1){
        var DateCol = "K9";
        var curDate = Utilities.formatDate(new Date(), "GMT+01:00", "hh:mm");
        var rowIndex = range.getRowIndex();
        var colIndex = range.getColumnIndex();

        // May need to set up multiple ranges like this and check all ranges if
        // checked fields are not in adjacent cells
        var watchRange = { 
            top : 11,         // start row
            bottom : 109,     // end row
            left : 2,        // start col
            right : 12,        // end col
        };
        // Exit if we're out of range
        if (rowIndex < watchRange.top || rowIndex > watchRange.bottom) return;
        if (colIndex < watchRange.left || colIndex > watchRange.right) return;

        var currentValue = range.getValue();
        currentValue = currentValue.replace(/^\s+|\s+$/g,""); //"trim" kludge

        if (currentValue.length != 0){

            // Set a column to show last edit date
            SpreadsheetApp.getActiveSheet().getRange(DateCol).setValue(curDate);

        };
    }else if{
    //Check the other range
    return;
    };
}

Based on what Ruben told me, I have modified my script and now I have this:

function onEdit(e){
  var curDate = Utilities.formatDate(new Date(), "GMT+01:00", "hh:mm");
  var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Test2');
  var colInicio = e.range.getColumn();
  var filaInicio = e.range.getRow();
  var ref = e.range.getA1Notation(); // Notación tipo A1 o A1:B2
  var range = e.getRange();
  var colIndex = colInicio.getColIndex();
  var rowIndex = filaInicio.getRowIndex();

  var watchRange1 = { 
    top : 11,         // start row
    bottom : 109,     // end row
    left : 3,        // start col
    right : 11,        // end col
  };

  var watchRange2 = { 
    top : 11,         // start row
    bottom : 109,     // end row
    left : 13,        // start col
    right : 21,        // end col
  };

  if(rowIndex >= watchRange1.top && rowIndex <= watchRange1.bottom && 
  colIndex >= watchRange1.left && colIndex <= watchRange1.rigth && 
  range.getValue() != 0){
    var DateCol1 = "K9";
    SpreadsheetApp.getActiveSheet().getRange(DateCol1).setValue(curDate);

 }else if (rowIndex >= watchRange2.top && rowIndex <= watchRange2.bottom && 
 colIndex >= watchRange2.left && colIndex <= watchRange2.rigth && 
 range.getValue() != 0){
    var DateCol2 = "U9";
    SpreadsheetApp.getActiveSheet().getRange(DateCol2).setValue(curDate);
 }else{
    //if test
    var DateCol1 = "K9";
    SpreadsheetApp.getActiveSheet().getRange(DateCol1).setValue("Fallo");
 }
}

When trying to run this script I get this error: Cannot read property "range" of undefined. (line 4, file "Day1")

I'm still pretty stuck with the script

I detect that the problem is before the if, but I can't solve it.