/usr/share/tcltk/tcllib1.16/otp/pkgIndex.tcl is in tcllib 1.16-dfsg-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | # pkgIndex.tcl -*- tcl -*-
if {![package vsatisfies [package provide Tcl] 8.2]} { return }
package ifneeded otp 1.0.0 [list source [file join $dir otp.tcl]]
|