Leaving behind Vodafone and Airtel in BB Tariff war BSNL revised their Blackberry billing plans for pre-paid as well as for post-paid customers (unlike other vendors). The new Blackberry plan of Rs 399 allows you unlimited browsing, 10-pop3/imap email accounts, and Instant messenger services but you can not download Apps on your mobile.
There are different ways to get the apps on your mobile through this plan also like using some alternate browser.