Time zone and population of the players in chessdotcom.
US is GMT-8, UK is GMT+0, Bagdad is GMT+3, Moscow is GMT+3, Bombay is GMT+5.30.
I believe that next to Indians is British. Russia, being in the same time zone, has only 17910 population (1/15 of India), and has higher average rating (tho not material).
The nationality of the people you play against depends very much of the time of day you are playing and of course your own time zone.