If you have a time machine and you go back in time to when you had 6 apples and then return to the present, the number of apples you have in the present would not automatically change simply by virtue of traveling back in time. Time travel in this scenario would just mean you are observing or interacting with a past event. Unless you actively change the past by, for example, preventing yourself from eating those 6 apples, the situation in the present remains the same.
However, time travel is a concept that is often associated with paradoxes and theoretical consequences. If we entertain the fictional scenario where you could change the past, then if you went back and stopped yourself from eating those 6 apples, you might come back to the present to find you have more apples than you did before. But this enters the realm of science fiction and the many interpretations of how time travel could potentially work.
In reality, time travel to the past is not possible based on our current understanding of physics, so the number of apples you have today would remain at 10, regardless of what happened last week.
If you were to travel back in time and change the course of events by eating 6 apples that you did not eat before, you would be altering the past, which could potentially change the present. This is known as the "grandfather paradox" or a causal loop, where changes in the past have direct consequences on the present.
In this hypothetical and fictional scenario, if you eat 6 additional apples in the past, you might return to the present to find that you have 6 fewer apples than you originally had because those actions would have altered the timeline.
However, these are all speculative ideas based on science fiction and time travel theories. In practical terms, as time travel to the past is not physically possible with our current understanding of the universe, there is no actual method to change past events, and thus, the number of apples you have in the present would remain the same. If you have 10 apples today, you still have 10 apples, regardless of any imagined time travel scenarios.