My guess would be that if it is a legit game used uniform, that it is from the women’s team.
I have seen a couple of occasions in the past, where some people on EBAY have listed a UTEP women’s uniform for sale, but stated that they were used men’s uniforms. You would know pretty quickly once you get the item, if it was a men’s or women’s?, but might not be able to determine until then. Just based on how small it looks, I would guess that if this is a legit used uniform, that it is from the women’s team? Maybe you can look for some old women’s game photos to try and confirm.