This is a genuine Maruti Suzuki Right-Hand (RH) Outside Mirror Cover (officially cataloged as Cover, Mirror Visor RH). It is the cosmetic cap that clips onto the back of the driver-side (in India) wing mirror assembly.
Maruti Suzuki Swift (2nd Generation, 2011–2017)
Maruti Suzuki Swift Dzire (2nd Generation, 2012–2017)