"pulcher" is a fairly elementary piece of Latin vocab. It's in Book I of the Cambridge Latin Course, for example. This is much the same in other courses. So anyone, Indian or not, who has done basic Latin in school is likely to have encountered it and hence be aware of "pulchritude".

* https://www.dl.cambridgescp.com/dl_course/book-i

A random other example: https://www.ocr.org.uk/Images/221512-gcse-latin-j282-defined...