Go for Spice C810 which is an open market CDMA phone and can run Reliance, Tata as well as Virgin connections. It has all the regular features like MP3, 1.3 MP Camera, FM,etc along with Bluetooth and a 3.5 mm jack. You can't get a better deal in 6k. Other options are Samsung Max and Samsung mPower 309. Hope that helps.
And I forgot to add that Spice C810 has a huge battery of 2000 mAH so you don't have to charge the phone for few days if not used excessively.