Question

what is the direction of magnetic field inside the bar magnet

Answer 1

So the field lines travel outwards from one side of the loop, the North pole, round to the other side, the South pole, then go inside the loop to complete their circuit. This has to happen because magnetic field lines cannot begin or end so they always have to form closed loops.

Answer 2

Inside the bar magnet the magnetic field moves in the direction from South to North.