India, likely. https://en.wikipedia.org/wiki/Indian_numbering_system

This is formatted as “lacs” or “lakhs”.

A “lac” is equivalent to 100 thousand.

So it would be colloquially said as 53 lacs 80 thousand.

I would guess Japan. Looks like the "man" concept they have to group numbers by 10k.

Edit: it seems to be also the case in other east asia countries, see this link https://en.wikipedia.org/wiki/Myriad#East_Asia

Japan and China use regular Western comma grouping for Latin numerals. The myriads are used only when using Japanese/Chinese numerals: １万円 for 10,000 yen, ２億円 for 200,000,000.

Thanks, I didn't know the formatting was following rules of Latin/Roman numerals. I remember having difficulties when learning to group numbers by 10k (with the -man suffix) during japanese courses more than a decade ago, I always assumed that was used everywhere.

Downvoted for a wrong guess? That's a bit harsh...

Yeah India