I assume N900 is not yet launched by Nokia in India. But I see few stores selling them. Not sure how do they provide warranty/customer support. You may want to ring and find it out.
http://www.srivasavimobiles.com/prod...d=Nokia%20N900

If it is a screen issue give a try in local mobile repair shops who fix N97 screens. I assume there should be some similarity between the N97 screen and N900 screen. Hope you are aware that once the phone is repaired by any third parties you lose the manufacturer warranty.