你好。下面，我把你提的这个问题中，里面所有的选项句子作一分析，请参考。
1. Tom was out. 汤姆出去了，不在家。（指过去的情况，也许在昨天，也许是刚才）
【举例说明】Tom was out when I called at his house.
2. Tom is out. 汤姆出去了，不在家。（指现在的情况，跟句1的差别是时间不同）
【举例说明】Tom is out. He is not here. He will be back in an hour.
3. Tom will be out. 汤姆将要外出。（将来时态）
【举例说明】Tom will be out. Now he is dressing up.
4. Tom has been out. （恕我直言：这个句子的意思表达不清。）
正确的表达应该是，在句子后加一个表示时间段的状语，如：all night, since last week, for three days等。因为单独Tom has been out.这个句子，意思不知所云。改为：Tom has been out all night.
【举例说明】—I haven’t seen Tom recently. —He has been out since last week.
5. Tom is off. 汤姆离开了，不在这儿。（跟out不同的是，off强调“离开，不在此地”，而out强调“外出，在外面”。）
【举例说明】—Is Tom still here? —No, he is off.
6. Tom has gone out. 汤姆出去了，不在家。（现在完成时，强调对现在的影响。从动作发生的时间考虑，Tom was out.跟Tom has gone out.最为接近。虽然时态不同，但都是过去发生的情况。）
【举例说明】—Is Tom at home? —No, he has gone out.