Um premade COILS (like prewrapped that you install yourself?) or fully manufactured coil HEADS? I don't know KT enough to even know if they make or do not make prefabricated coils to install into an RTA deck but to the best of my knowledge they don't, although I am also quite prepared to be wrong on that. Hmnm.
You need coils that will fit an RTA not a drop in tank, so if they're premade coils for tanks, they will not work with your Lemo RTA I don't think.
It's not the resistance of the coils in your tank on a regulated mod that determine battery safety, but how much wattage you use. Although most regulated mods will have a lower limit on resistance, but I'd say 0.5 is going to far exceed that threshold most likely. Where did you get the battery was it from a recommended vendor? As if you have a rewrap or other type of battery it's not going to be possible to figure out exactly what battery you HAVE. With most regulated mods if you try to exceed the battery's capacity protection will kick in and it will refuse to fire, well that is what is SUPPOSED to happen but it doesn't always happen and while batteries in regulated mods are far safer, you still need to KNOW WHAT YOU have to know if you are in a safe zone or not.
Could you say more about what you have, where you got it, and what exactly you are trying to achieve? There may be some remedial purchasing that may have to happen, as you 99 times out of 100 maybe more, can't use drop in coils in RTAs. that's not how it works.
Good luck and the more information the better I think
Anna