This is from a post at RFL: (some days and years are messed up.. so its just for FYI)
sir i gt sme marathons list nd hve find sme marathons list----
The Thane Varsha Marathon will be held at Thane in Maharashtra on July 14, 2002, the Tata Steel Half Marathon at Jamshedpur on July 29, the Travancore Marathon at Thiruvanathapuram on August 9, the Chennai Marathon on November 2, the Salwan Mini Marathon in Delhi on November 3 and the Indira Marathon in Allahabad (UP) on November 19. ( dnt knw these r curently running), pls get these marathons information, ill also try, and
1 mre web site i find thts www.siligurimarathon.com ----dnt knw whn its organised, but 2007 marathon is sucesfull acc to the website information "