I think Buddhism involved Sanskrit, but Sanskrit is a language.
Are questions about Sanskrit off-topic?
I think that people previously (a bit more than a year ago) argued that questions about Pali, specifically about learning Pali, were not on-topic -- see "A good source to learn the Pali language? [closed]".
I'm not sure why that is, but it may be partly because there are an infinite number of questions you could ask, and they're not interesting to people who don't want to learn the language (and flooding the site with questions about Sanskrit would alter the main interest of this site).
Note that Buddhism also involves Chinese, and other languages, but those languages too are not themselves on-topic on this site.
So, for example, I suggest that you shouldn't ask questions about Sanskrit grammar etc.
On the other hand if the question is directly related to Buddhism then it's more on-topic, for example,
I don't think we've had that type of question before, so I don't know whether such questions will even be answered (i.e. whether there are users on this site who are able to willing to answer them).