HI the phone which you are having might work in Nepal only if it is unlocked one .Else if the phone is locked to some other network provider then you can't use it in Nepal until you unlock it .You can easily unlock your phone using sites like UnBBlock.com here they are rendering unlock code for all blackberry mobile models at reliable cost .Else if you want to unlock some other mobile model then have a look at sites like MobileUnlockSolutions.com here they are rendering unlock code for all mobile models at reliable cost .After unlocking your phone you can freely use it with any GSM sim in Nepal...