Even though
I have used Tata Photon Plus (CDMA)prepaid for more than a year (before jumping in to 3G sim+ unlocked 3G data card band wagon )
and my wife has a company given Post paid Reliance Net Connect even now (CDMA),
I will suggest you get a unlocked 7.2 mbps data card from ebay.in at a very low price.
HUAWEI E1731/E1732/E1750c/E173 between Rs 1275-1399 (including courier)
Avoid ZTE modems if possible.(Most voda data cards are ZTE)
Avoid BSNL proprietory locked data cards like Bubonic Plague (micromax,teracom,Zte etc)
you have two options
1.Buy factory never locked modems from Letsbuy/flipkart @ rs 1600-2000 .
2.Ebay unlocked data cards ( no 3.6 mbps stick to Huawei 7.2 mbps cards ) below Rs 1400.
Get 3G prepaid sim from a few companies and check signal strength at your home with a small 3 G data pack (Rs 100-100 mb like that)
Then go for 4 GB/6GB/10 GB dat arecharge. average cost Rs 600-1200/30 days.
I have 4-5 data cards lying unused in my house. Then you know I have learnt by trial and error !!
Now I want only 21 mbps data card!!