hello friends i want to buy a nokia lumia 900 which will be pretty costly in india many sites have rated it about 30k but it is really cheap in usa here is the link
Nokia Lumia 900 - Nokia - USA
so i want to ask a ques that will any sim i.e any indian sim will be supported in that phone or not if yes please tell me is this a very nice phone ??and will it be able to upgraded to windows 8??
To answer your questions...
I think the first question is already answered perfectly... the one abt price difference..
For the other questions,
2. Almost all the nokia phones r quad band and hence support all operators and u can choose any GSM sim... bt it might only support micro sim..
3. Nice is a perspective.. the above guys have mentioned the cons.. there is a windows phone thread.. go there to see the pros... there r some ppl who prefer windows due to the fluidic UI..
4. There will be no update to Windows 8 unless there is a miracle.. Windows has kinda made it clear indirectly... there wud be updates and fixes since its Nokia.. bt an Android like upgrade to next OS is highly unlikely...
Tell me 1 Nokia Phone after the N8 that has been a hit

Imo stay away from Windows OS in the phone, its no good!
I would not totally put a lock on Windows OS.. for all I hear, Windows 8 cud be something... dunno if Nokia will be there to witness it... unless taken over by Microsoft...