Probably BMTC Dumping old busses to Mysuru

From past few weeks I am seeing few busses whose design and color is not similar to Mysuru City Bus and have a registration no., KA 57. I spotted one such bus near Agrahara circle last month. Since 2 weeks I am seeing one such bus whenever I go outside. These busses are releasing think black smoke and causing lot of pollution. KSRTC is acquiring 100s of luxury electric bus for Bengaluru and most probably dumping old busses to Mysuru.