Question

tum kaha ja rahe ho translste in english

Answer 1

The translation would be
Where are you going?

Answer 2

The translation to this would be where are you going.

Tum Khn Jaa rhe ho is simply enquiring about as to where the person is going.

Where means khn and going means Jaa rhe ho.

So this is the justification for the translation of the text which is written in the question.