I checked my dipstick in my 2010 Lincoln town car and it was bone dry so I added 6 quarts and it was still bone dry. I put the key in the ignition and started it and let it run for about 20 minutes in my driveway and when I came out of my house to check the oil it smelled like oil was burning.
Depending on the engine you have the capacity for your engine oil is 5.5 or 6 quarts. It is impossible for you to add 6 quarts of oil in this engine and read an empty dipstick without oil leaking from the fill point or underneath the engine in that short amount of time. I am convinced that you are looking at the wrong dipstick, and overfilling the engine with oil. The only answer I can give you is to read the owners manual and become familiar with how to check and maintain fluid levels. Or have someone knowledgeable on this help you learn. This car should not be started at all until it is looked at. 6 quarts of extra oil can possibly cause significant damage to your engine. If by chance it has no engine oil it would destroy the engine no doubt about it.