"Two" appears as "दो" (do) in Hindi in the 2000 INR notes. This looks correct to me: https://en.wikipedia.org/wiki/File:2000_INR_Rev_2016.jpg (see the left edge of the note just below the string "2016").

If you are talking about "दोन" (don) appearing twice within the pink rectangular box, that's Konkani and Marathi, not Hindi. Two is indeed written as "दोन" (don) in Konkani and Marathi.

Then the question arises why write it like that twice. Why is not written in Hindi even once?

I thought I have explained that already in my previous comment. It is written like that twice because "Two" is "दोन" in Konkani as well as Marathi. Both languages are used in the language panel of the reverse side of the note.

"Two thousand rupees" (in English) = "दोन हजार रुपया" (in Konkani) = "दोन हजार रुपये" (in Marathi).

This is nothing new about the new 2000 INR notes. This is true for the older 5 INR, 10 INR, 20 INR, 50 INR, 100 INR, 500 INR and 1000 INR notes as well. The language panel shows only 15 of the 22 official languages of India, in alphabetical order. The 6th language in the language panel is Konkani and the 8th one is Marathi.

I have also explained in my previous comment that the denomination is also written in Hindi. Why do you think it is not written in Hindi even once? In fact, the denomination is written in Hindi on the reverse side of every note, outside the language panel, either at the bottom left corner or at the left edge. In fact, in the new 2000 INR notes, "दो हज़ार रुपये" is written in Hindi at the left edge of the reverse side of the note.

I can read Urdu and from what I can make out in images of the note, the Urdu text is fine. The font could have been better. The orthographic sign that makes the H in 'hazaar' is correct; the 'be' nuqta is a different shape. There should have been a hair-width's space after the 'dal' in 'do', but it is easily readable as 'dal' and not 'lam' as some people are claiming.

Yes. So, can I read Urdu and the hey looks like a bey. ب has the dot below it which you can clearly see in all images. ح doesn't have any dots beneath it.

Hazaar is spelt with a choti he which does have that inverted comma under it (clearly distinguishable from a nuqta by the elongated head shape, as it is on the note (but it is tiny because the font size is tiny)).

Here's an example of hazaar with the spelling I mean: https://lh3.ggpht.com/FXu7LY_Ki5uDcYTcOWwMSxAL0lC9ttGLbNZrrT...