AK is a very strong starting hand, but how you choose to play AK preflop will need to take into account how tight/loose the player who raised is and their position at the table.

Generally in 6-max games you want to re-raise with AK in any position, especially OOP when the plan is to take it down preflop.

If a player who is playing fairly loose raises in late position, then you should 3bet them in the blinds with AK.

If the raiser in late position was a relatively tight player, then it would be a better play to just flat call in the blinds and decide what to do post flop depending on the board texture. You don't want a tight player folding hands we dominate like AJ or AQ. If a A comes on the flop, we will likely win a decent sized pot.

Another example is if you raise in early position when you have AK and someone in late position re-raises. If the 3bettor is a loose player then i will usually 4bet in this spot. This is because you are likely ahread of their 3bet range and you want to take initiative in the hand. Playing AK out of position when you don't have initiaitve in the hand, which is the case if you flat call the 3bet, can be difficult to play, so its easier to just 4bet them and cbet most flops.