Hello,
Is writing a dialogue the same as writing a paragraph?
Take this example.
Write a mini-dialogue or a short conversation that is possible to occur at a proper place.
You choose ONE of the following topics:-
What if I start my dialogue with this greeting.
John: Hello, Mike, how are you?
Mike: Hello, John, I’m fine thanks, and you?
John: I’m fine too, what do you know about human rights?
A dialogue and conversation are the same thing, so that format looks okay to me.
I suspect your content would be ‘off’ if you follow the prompt ‘possible to occur at a specific place’. I think the examiner probably means something like a conversation at an airport, a bus station, a sports centre, a bus rink, in a shop, etc. (possibly a dialogue possibly between a member of staff and a customer or between two business people, for example, at the office. It might also be at a party or at a barbecue, etc, which would lend itself more to your starter, except that suddenly hurling yourself into a human right debate would be a very strange thing to do at such an event.
I really can’t tell why in our university here in Egypt the professionals are like this, they always have strange questions in their exams!
A dialogue truly should be about a conversation:
At the supermarket, between the cashier and the customer or between two customers discussing about what they are going to buy.
At a bank, money exchange, job manager room, etc…
At school, between a teacher and a student.
But human rights, looks like he wants a paragraph instead, that’s too odd 
He didn’t even state with who and where exactly the dialogue will run.
But now I am asking, can I start with: Hello, how are you? and the answer of that in any dialogue?
Can this work Beeesneees?
If he wants a paragraph, then I would not expect the same format. I would expect it to be written like a story, rather than a script.You can start most conversations with ‘hello, how are you?’ if you wish. It may sound very formal and stilted in some situations.
What does “human rights” exactly mean Beeesneees?
Can I talk about for an example, a teacher has the rights to teach students at school.
I wouldn’t consider that to be a topic about human rights.
Human rights are basic rights and freedoms which everyone should expect.
To use those as examples, I think you would need to turn those on their head at the very least:
The students have a right to be taught well.
The patients have a right to expect a certain amount of care.
The children have a right to be looked after by their parents.
I suggest you read up about human rights if you intend writing about them.
equalityhumanrights.com/human-rights/