When an article is registered under a chartered (eligible to train article under him) doing job in a firm, and if that chartered leaves the job from that firm then can an article get transfer to other principal of his choice in other firms......

First tell me that your Principal (CA) is as a partner in that firm.....?

If yes than, now what he is doing. A job OR as a partner in another firm..?

If as a partner in another firm then, you don’t have an option to leave your current Principal.

If he has joined another firm & that firm is more than 50 km. from your current office then you can approach ICAI for termination of your Article ship.

Actually this is my friend's case not mine. His principal was not working as a partner, he was a audit manager in the previous firm and now he has joined another firm as a audit manager there.