If you're able to share images of the laundry tags that might help with identifying a year, but realistically most pants like this will have a generic name that probably won't help you much (like Nike Essential Trouser or something).
As an aside, RN #56323 is simply the Registered Number for Nike as a legal requirement under US laws around textiles and manufacturing. You may also see CA #05553 on products, which is just the Canadian equivalent. This is pretty universal so unfortunately doesn't give any real information whatsoever.
If you're able to share images of the laundry tags that might help with identifying a year, but realistically most pants like this will have a generic name that probably won't help you much (like Nike Essential Trouser or something). As an aside, RN #56323 is simply the Registered Number for Nike as a legal requirement under US laws around textiles and manufacturing. You may also see CA #05553 on products, which is just the Canadian equivalent. This is pretty universal so unfortunately doesn't give any real information whatsoever.