Government-owned telco Bharat Sanchar Nigam Limited has increased the validity of a special tariff voucher of Rs 198 by five days. BSNL’s Rs 198 prepaid plan gives 2GB daily data. BSNL revises Rs 499 plan: BSNL has further revised Rs 499 prepaid plan to offer 2GB daily data from June 1 at no additional cost. BSNL Rs 499 plan now …