I've interacted with several HS graduates from India, and those who opt for CS in HS (11th and 12th grade; usually ages 16-17) are usually taught C++ in Turbo C++ 3.0. This release of Turbo C++ was released in 1990.
That's... not great. For reference, the C++ programming language was first standardized in 1998.
Thus, most graduates never learn proper C++ in the sense that a lot of what they're taught doesn't even compile on modern compilers and they aren't aware of many new* features.
That said, this project is still pretty impressive for an HS student, even if it's written in ancient C++ and requires DOS to run :)
*new = anything introduced to C++ in the last three decades (after 1991).
However, apparently they've introduced Python3 last year, so hopefully the situation will improve :)