Sub RasponKomora()
    Dim kolicinaCisterne As Double
    Dim kolicineKomora() As Double
    Dim rezervoar1 As Double
    Dim rezervoar2 As Double
    Dim razlika As Double
    Dim postotak As Double
    
    kolicinaCisterne = Range("G6").Value
    kolicineKomora = Range("G7:G11").Value  <<<<<<<<<run-time 13 type mismatch errorrr
    rezervoar1 = Range("E2").Value
    rezervoar2 = Range("E3").Value
    postotak = Range("A1").Value
    
    razlika = (rezervoar1 - rezervoar2) * (1 + postotak)
    
    For i = 1 To 5
        If kolicinaCisterne > 0 Then
            If kolicineKomora(i, 1) <= razlika Then
                rezervoar1 = rezervoar1 + kolicineKomora(i, 1)
                razlika = razlika - kolicineKomora(i, 1)
                Range("e7").Offset(i, 0).Value = "R-1"
            ElseIf kolicineKomora(i, 1) <= kolicinaCisterne Then
                rezervoar1 = rezervoar1 + kolicinaCisterne
                razlika = razlika - kolicinaCisterne
                Range("e7").Offset(i, 0).Value = "R-1"
            Else
                rezervoar1 = rezervoar1 + razlika
                razlika = 0
                Range("e7").Offset(i, 0).Value = "R-1"
            End If
            kolicinaCisterne = kolicinaCisterne - kolicineKomora(i, 1)
        Else
            Range("e7").Offset(i, 0).Value = ""
        End If
    Next i
    
    Range("F2").Value = rezervoar1 - Range("E2").Value
    Range("F3").Value = rezervoar2 - Range("E3").Value
End Sub

Option Explicit
Sub CalculateCompartmentsPerReservoir()
' s - Source
Const SRC_COMPARTMENTS As String = "G7:G11"
Const SRC_RESERVOIRS As String = "E2:E3"
Const SRC_PERCENTAGE As String = "A1"
' d - Destination (Result)
Const DST_COMPARTMENTS_COLUMN As String = "F"
Const DST_RESERVOIRS_COLUMN As String = "F"
Const DST_ABBREVIATION_1 As String = "R-1"
Const DST_ABBREVIATION_2 As String = "R-2"
Const DST_EMPTY_RESERVOIR As String = "Empty"
Dim ws As Worksheet: Set ws = ActiveSheet ' improve!
' c - Compartments (Komore)
Dim dcrg As Range, scData(), CompartmentsCount As Long
With ws.Range(SRC_COMPARTMENTS)
CompartmentsCount = .Rows.Count
scData = .Value
Set dcrg = .EntireRow.Columns(DST_COMPARTMENTS_COLUMN)
End With
' r - Reservoirs (Rezervoari)
Dim drrg As Range, srData(), ReservoirsCount As Long
With ws.Range(SRC_RESERVOIRS)
ReservoirsCount = .Rows.Count
srData = .Value
Set drrg = .EntireRow.Columns(DST_RESERVOIRS_COLUMN)
End With
' Ratio (Omjer)
Dim Ratio As Double: Ratio = 1
With ws.Range(SRC_PERCENTAGE)
If VarType(.Value) = vbDouble Then
Ratio = Ratio + .Value
End If
End With
' Destination Arrays
Dim drData() As Long: ReDim drData(1 To ReservoirsCount, 1 To 1)
Dim dcData() As String: ReDim dcData(1 To CompartmentsCount, 1 To 1)
' Loop 1
Dim CompartmentFuel, n As Long, WouldBeReservoir2Fuel As Long
For n = 1 To CompartmentsCount
CompartmentFuel = scData(n, 1)
If VarType(CompartmentFuel) = vbDouble Then
WouldBeReservoir2Fuel = srData(2, 1) + CompartmentFuel
If srData(1, 1) < WouldBeReservoir2Fuel * Ratio Then
srData(1, 1) = srData(1, 1) + CompartmentFuel
drData(1, 1) = drData(1, 1) + 1
Else
srData(2, 1) = WouldBeReservoir2Fuel
drData(2, 1) = drData(2, 1) + 1
End If
Else
scData(n, 1) = 0
dcData(n, 1) = DST_EMPTY_RESERVOIR
End If
Debug.Print n, srData(1, 1), srData(2, 1), WouldBeReservoir2Fuel
Next n
' Loop 2
' The fuel in the 1st compartments will be used to fill the 1st reservoir.
' Switch the expressions in the inner If statement
' to fill the 2nd reservoir with the fuel of the 1st compartments.
For n = 1 To CompartmentsCount
If Len(dcData(n, 1)) = 0 Then
If drData(1, 1) > 0 Then
dcData(n, 1) = DST_ABBREVIATION_1
drData(1, 1) = drData(1, 1) - 1
ElseIf drData(2, 1) > 0 Then
dcData(n, 1) = DST_ABBREVIATION_2
drData(2, 1) = drData(2, 1) - 1
End If
End If
Debug.Print n, drData(1, 1), drData(2, 1), dcData(n, 1)
Next n
' Write to the worksheet.
drrg.Value = srData
dcrg.Value = dcData
' Inform.
MsgBox "Compartments per reservoir calculated.", vbInformation
End Sub

 Dim kolicineKomora() As Double

Dim kolicineKomora() As Double
Dim i As Long
Dim array_index As Long  'for calculating items in array
array_index = 0
For i = 7 To 11
ReDim Preserve kolicineKomora(array_index)
kolicineKomora(array_index) = Cells(i, "G")
array_index = array_index + 1
Next i
'print the items in kolicineKomora()
For i = LBound(kolicineKomora) To UBound(kolicineKomora)
Debug.Print i; kolicineKomora(i)
Next i
Erase kolicineKomora