The Anti Corruption Bureau (ACB), Bengaluru has filed a chargesheet against six persons, including two senior prison officials of Karnataka and V.K. Sasikala, a close aide of former Tamil Nadu Chief Minister Jayalalithaa, in a corruption case of illegally providing preferential facilities when Sasikala was lodged in the Central prison in Bengaluru while she was serving a sentence in a corruption case against Jayalalithaa.