if the VBA is correct, below is the modification:
    ' Find the smallest closest rebar size
    For Each smalest In rebars
        If smalest < crosssection And smalest > Fix(crosssection) Then
            result.Add smalest, smalest & " - " & rebars(smalest)
        End If
    Next smalest
    
    ' Find the closest rebar size
    For Each closestRebar In rebars
        If crosssection <= closestRebar And closestRebar < Round(crosssection + 2, 0) Then
            result.Add closestRebar, closestRebar & " - " & rebars(closestRebar)
        End If
    Next closestRebar
    
    ' Print the results
    If result.Count > 0 Then
        MsgBox "Rebar results: " & crosssection & vbCrLf & Join(result.Items, vbCrLf)
    Else
        MsgBox "Rebars not available. Check input: " & crosssection
    End If