For any piano (keyboard, digital or acoustic), is the piano made or tuned differently for Indian and western music? Or, can the same piano be used for both?
I think the main problem in using a piano for Indian music is that quarter tones are often employed. For other instruments, special versions are sometimes made specifically to add them in addition to the normal half-step distances between notes.
It would be easy for a trombone to handle it, through the player would have to learn new slide positions. Since the slide allows them to play any pitch in their range, it could be done.
For a trumpet, some makers produce them with an extra 4th valve that lowers the pitch by a quarter step. When combined with the normal three, the player can play scales with quarter tones in them. There are also quarter tone clarinets, etc. but they are quite rare.
String instruments (without frets) can obviously play them, because they can position the hand anywhere along the neck.
It might be possible to reprogram a digital piano to remap the keys for quarter tones, but that would be very confusing to a conventional piano player.
You could also have much more complicated keyboard layout allowing extra keys for the quarter steps in between each of the normal 88-keys for a standard piano, but it would likely be extremely difficult to learn to play.
I think it might be easier to approach by having an additional pedal effect that would lower the step of a normal key by 1/4, but that would not work when you wanted to play chords with only some of them lowered a 1/4 step.
Normally, without very bizarre custom work, pianos are not considered capable of playing quarter tone music.
The main reason traditional keyboard instruments like the piano are unsuitable for playing Indian music is because Indian music uses a lot of smooth grace notes and glides between the notes. Some Indian ragas do use microtones in a very deliberate way, but they are not ubiquitous by any means. The reason Indian music sounds like it uses a lot of microtones is because of the glides, which include intervening pitches between the start and end notes. Even in ragas that do not use any microtones, the grace notes and glides can make the standard notes sound very different from what they sound like when sung/played straight.
Having said that, the harmonium (which is a keyboard instrument similar to the accordion) is popularly used as an accompanying instrument. Traditionally, harmoniums had equal-tempered tuning. Eventually some harmoniums began to be customized and just-tuned to the player or singer's preferred key. Then they came up with something called a scale-changer harmonium, which allows you to slide the keyboard up or down using a mechanical device. Personally, though, I don't like the harmonium very much for Indian music.
A lot of digital keyboards and other instruments these days have very interesting new features that may be great for Indian music. I am quite impressed with this iPad app called GeoShred, for instance: