Option Explicit

Function IsInter(r As Range, t As Range) As Boolean
    Dim first As Range
    Set first = r
    
    Dim last As Range
    Set last = r.Cells(r.Count)
        
    If first.Row <= t.Row Then
        If t.Row <= last.Row Then
            If first.Column <= t.Column Then
                If t.Column <= last.Column Then
                    IsInter = True
                    Exit Function
                End If
            End If
        End If
    End If
    IsInter = False
End Function

Private Sub Worksheet_Change(ByVal Target As Range)
    If IsInter(Range("A1:A10"), Target) Then
        If Target.Value <= 5 Then
            Call MsgBox("min")
        End If
    End If
    
    If IsInter(Range("A11:A15"), Target) Then
        If Target.Value <= 10 Then
            Call MsgBox("min")
        End If
    End If
    
    If IsInter(Range("B1:B15"), Target) Then
        If Target.Value <= 3 Then
            Call MsgBox("min")
        End If
    End If
End Sub