There are 6" canister lights throughout my home. The bulbs are expensive to replace and are not efficient. I'm looking to see if there are kits that maybe you can screw in to where the bulb used to go and changes it into halogen. Is this possible?

They make halogen reflector lamps. They are called PAR lamps. Usually with a CAP suffix.
A typical example would be a 50 PAR30/CAP