This is makeindex, version 2.15 [TeX Live 2021] (kpathsea + Thai support).
Scanning input file tsvmman.idx....done (11 entries accepted, 0 rejected).
Sorting entries....done (38 comparisons).
Generating output file tsvmman.ind....done (30 lines written, 0 warnings).
Output written in tsvmman.ind.
Transcript written in tsvmman.ilg.