/usr/lib/vtk-5.10/tcl/vtk/ is in tcl-vtk 5.10.1+dfsg-2.1build1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/vtk-5.10/tcl/vtk/vtk.tcl
/usr/lib/vtk-5.10/tcl/vtkbase/vtkbase.tcl
/usr/lib/vtk-5.10/tcl/vtkcharts/vtkcharts.tcl
/usr/lib/vtk-5.10/tcl/vtkcommon/vtkcommon.tcl
/usr/lib/vtk-5.10/tcl/vtkfiltering/vtkfiltering.tcl
/usr/lib/vtk-5.10/tcl/vtkgeovis/vtkgeovis.tcl
/usr/lib/vtk-5.10/tcl/vtkgraphics/vtkgraphics.tcl
/usr/lib/vtk-5.10/tcl/vtkhybrid/vtkhybrid.tcl
/usr/lib/vtk-5.10/tcl/vtkimaging/vtkimaging.tcl
/usr/lib/vtk-5.10/tcl/vtkinfovis/vtkinfovis.tcl
/usr/lib/vtk-5.10/tcl/vtkinteraction/Interactor.tcl
/usr/lib/vtk-5.10/tcl/vtkinteraction/bindings-iw.tcl
/usr/lib/vtk-5.10/tcl/vtkinteraction/bindings-rw.tcl
/usr/lib/vtk-5.10/tcl/vtkinteraction/bindings.tcl
/usr/lib/vtk-5.10/tcl/vtkinteraction/setget.tcl
/usr/lib/vtk-5.10/tcl/vtkinteraction/vtkinteraction.tcl
/usr/lib/vtk-5.10/tcl/vtkio/vtkio.tcl
/usr/lib/vtk-5.10/tcl/vtkparallel/vtkparallel.tcl
/usr/lib/vtk-5.10/tcl/vtkrendering/vtkrendering.tcl
/usr/lib/vtk-5.10/tcl/vtktesting/backdrop.tcl
/usr/lib/vtk-5.10/tcl/vtktesting/colors.tcl
/usr/lib/vtk-5.10/tcl/vtktesting/grab.tcl
/usr/lib/vtk-5.10/tcl/vtktesting/mccases.tcl
/usr/lib/vtk-5.10/tcl/vtktesting/vtktesting.tcl
/usr/lib/vtk-5.10/tcl/vtkviews/vtkviews.tcl
/usr/lib/vtk-5.10/tcl/vtkvolumerendering/vtkvolumerendering.tcl
/usr/lib/vtk-5.10/tcl/vtkwidgets/vtkwidgets.tcl