I was sitting in a coffee shop alone (just with myself). The table I sat had two chair. Then a man came and asked me "May I?", and he pointed the chair which was in front of me. What should I answer if I meet the situation again? Shall I answer "Is not occupied", or "You can take it"? Or another?
Assuming that you want to give them the seat, you can respond with may:
- You may./You may use it.
This might be a little formal. More casually, you can say
- Go ahead.
- Sure./Sure thing.
There are many other options.
Your options work too.
- It is not occupied.
- You can take it.
In 5, you need a subject like it or the seat. 5 also seems a little stiff, so I don't recommend it.