Will try my best to keep updating this post with events (mostly close to Bangalore)...
2010
Upcoming events,
http://sunfeastworld10k.indiatimes.com/ - March 23rd - 2010
http://marathon.auroville.com/ - Feb 14 - 2010
http://www.goamarathon.in/ - March 07 - 2010
http://www.thehigh.in/
2009
Upcoming events,
Benguluru Walkathon - December 5th 2009
http://www.feetonthestreet.in/
http://www.toimidnightmarathon.in/home.html
Past events,
http://sunfeastworld10k.indiatimes.com/
http://www.kaveritrailmarathon.com/
http://www.vydehiandmallyaheart10k.com/
http://bsaherculescyclothon.in.com/
http://inside.nikeplus.in/ / http://inside.nikeplus.in/racedetails.php
http://www.bangaloreultra.com/
http://www.hyderabad10k.com/
m.m
http://minmaxmim.blogspot.com/2009/08/running-marathon.html