How can a player kill so many enemies using tanks?

I try to check but I can't, is there a hack for tanks?

https://battlelog.battlefield.com/bf4/pt/battlereport/show/1/1789757005414367104/816753520/

Skilled experienced players are capable of getting a lot of kills using any of the bf4 vehicles. They know the limits of the equipment, how to play, when to hide or push, often go for farming infantry to get high stats, etc. Totally doable, especially when there are a lot of new or unskilled players  on the server  that do not know or try to even take down the vehicle player, just like in your battlereport example.

But to answer your question - yes there are all sorts of cheats, the ones affecting vehicles are usually somewhat easy to spot by those who know how the game mechanics work.