This is an adult pair. The male has a deep magenta head with contrasting black collar and maroon patch on wing coverts. The female on the left has a blue-gray head and lacks the black collar. This species is endemic to the Indian Subcontinent where it is widespread but reported to be declining. It was formerly lumped with the similar Blossom-headed Parakeet (Psittacula roseata) of the Himalayas and Southeast Asia. The two apparently overlap without interbreeding. Canon PowerShot SX50 HS.
References:
Collar, N. (2016). Plum-headed Parakeet (Psittacula cyanocephala). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/54570 on 24 July 2016).
Rasmussen, P.C. & Anderton, J.C. (2012) Birds of South Asia. The Ripley Guide. Vols. 1 and 2. Second Edition. Smithsonian Institution. Michigan State University & Lynx Edicions, Washington. D.C., Michigan & Barcelona.