I haven't got the answer for what I asked for...
Discussion is happening between reply and revert.
I am looking for a similar word as please or kindly.... Can anybody help?
As Barb said, you have got your answer. There is no other single word you can use instead.
You could replace please with 'I would really be very grateful if you could possibly find a moment or two of your precious time to revert for clarification', but life's too short, and time's money in the business world.