I've had good experiences from Kala Kendar, they carry a good range of harmoniums, their website is listed everywhere on this site (chandrakantha.com). here's the site http://www.kalakendar.com/musicmain.htm. speak to Mickey, hes' the right guy to speak to over there.
Hi, You can visit Kala Kendra but they are are a bit expencive as I have visited there store.
If you want to get a good quality harmonium at reasonable price then you need to import it. I have done it, it realy works I have imported form the famous Pakrashi harmonium of kolkata, you can visit www.pakrashi-harmonium.com & mail them.