i had similar situation few months ago. don't rule out one way flights using different alliances, sometimes that turns out to be cheaper/comfort with routing. best bet is do a detailed search to/from bombay and get a dirt cheap fare to banagalore with indian websites like yatra/make my trip etc.
use MR travel site and UR travel search to figure out your best options. This way if you are able to find some flights say on continental or AA segment and use either the UR or MR site, you would even earn miles. Delta is fine too, mostly with air france options. delta flights from india to US are cheaper so if you are looking into doing 2 one way. with continental (EWR) or AA (ORD) you can get easily good options non-stop to delhi avoiding europe and surcharge.
even if that means you use your delta or other miles to get to EWR or ORD, with silver medallion you may get upgraded. again CO one way can work out to be great , mixed class (first class US to india, economy us segment) in 60k points, gives you the liberty to do do 2 different alliances if you have points scattered. and with chase UR points you can book that flight with points and earn miles on continental.
You can even do a status challenge with CO using your delta silver medallion and earn the required miles for silver with CO till 2013 with a little planning.
hope this rambling gives you ideas and resources.