can low level of brake fluid cause brakes to lock

Sorry, I don't quit understand your question or comments. Do you mean the brakes are locking up? as in they grab so hard the wheels skid? or are you saying they don't work? what do you mean by "car slows down as if braking engine drags to a stop"? If they are locking the wheels when you apply the brakes - No, low fluid cannot cause this. If they are not working when you apply the brakes - Yes, low fluid can cause this. If the fluid is so low the brakes have stopped working, we need to find out where the fluid is leaking at and fix the leak.