Hello, first of all sorry for my english mistakes (it is not my main language).

I have an Asus model X556U and i bought it two weeks ago, the problem is that my cousing pull while walking my laptop power cable, it does not fell or something worst, but when i looked closely to the charger entrance i notice that it was loose (it moves slightly to all directions except towards and backwards), for the moment i have not problems while charging it but i do not if it would break later or something worst 
https://gyazo.com/dda9224acbe42090c768021d4f72476c
Thanks for your answers  .
If your lucky just the jack body is loose and the 2 pins for + and - are still solid and not loose in the daughter or main board. Brand new laptop you could try to USE a warranty claim and see if its covered for repair or replacement of the laptop. OTHERWISE I'd look for a way to secure it from movement.

If it were my laptop and not covered by warranty for the damage. I'd open the laptop up and either replace the damaged daughter board that has the power jack on it -or- pour hot glue from a hot glue gun over the PLASTIC jack body without getting glue inside the jack and BOND the loose jack body back to the daughter board. This would make the jack body solid again. I've used hot glue before for projects like this one.

Then in future you need to be sure that the cord is not a tripping or clothes line problem. This is a very common problem to laptops. When using my laptops I place my foot on the cord with some slack to the laptop and this way if ANYONE snags it its only tugged between my foot and the wall outlet vs the hard yank to the power jack of laptop. We have a dog that always likes to get tripped up and its saved my laptops from damage by eliminating the cord from getting yanked out back of laptop.Just do nothing. You do not yet have a problem.
If it does become a problem, it can be managed.**
What I what to say is that prophylactic treatment may do more harm that the alternative . The loose connection is not likely to cause greater issues.

** Batteries can be charge with another device in the went of connector failure.

My advice: Leave it alone.