Are you looking to find the eastings and northings points for a specific location in the UK?
Here is a good way to roughly check the coordinated location of a Revit project in the UK. The website UK Grid Reference Finder is an excellent website to use to cross check that your model is situated in roughly the correct coordinate system. You can search either by location, Eastings and Northings points or longitude and latitude.
This tool should be used with consideration as it will not give you a completely accurate reading, but can be used to double check the coordinates of others models when you are having issues with models aligning through shared coordinates.