Excise duty on blended aviation turbine fuel adjusted with reduced rate for RCS UDAN flights and standard rate for others. Inserts two tariff entries into the Central Excise notification to treat blended aviation turbine fuel differently: a concessional excise rate for blended ATF drawn by selected airline or cargo operators for Regional Connectivity Scheme (UDAN) flights from designated RCS airports, heliports, or waterdromes, and a separate general excise rate for blended ATF otherwise. The amendment is promulgated under the Central Excise Act authority and takes effect on the notification's stated operative date.