Is it safe to buy customs iphone in chennai?

1. What all should i keep in mind b4 buying in customs

2. What are the questions i should ask the seller

3. What should i check when i get the iphone

4.is there a better option except buying it in retail showrooms r buy used 1's?

Don't buy any custom made at all.
its fakee. Get it from apple store or good stores that sells it.
if you can't afford new one, buy a used one but avoid fake one.take someone who has an iphone or has knowledge.
don't waste your money.

I want iPhone 5s