Kaz, I recommend a direct request to the schools you are interested in. They have to state this in their admissions policy which is a public document also held by the local authority. Many schools make this info available on their websites.
If however this is to make a case for admission to a schools that has refused already, you may need to check for example how the distance to school is calculated by the LA that has had the final say. Some use GIS-type maps that fail to take into account the actual route a child will take, so get yourself out on the ground with an old-fashioned measuring wheel and make a proper calculation. eg getting to a safe road-crossing point can add distance not perceived by an e-map.
Above all make friendly and reasonable approaches to school and LA staff involved - there are always fluctuations to school populations across a year and if a place becomes available they could be better inclined to you.