I checked with the networks (Not - BSNL) and most say that roaming is not part of the inclusive package (unlike BSNL where it is part of the package).
I am now looking at CDMA options, once again, BSNL is offering the best price plan; Rs.750/- for true unlimited data, no data cap. Only problem is that no roaming in Mumbai or Delhi (MTNL circles).
It's looking more like going with BSNL only, question is whether 3G or CDMA?
Using pre paid BSNL 3G sim with free all India roaming is not a bad idea. AVOID EVDO.CDMA.You will regret
But 7.2 mbps GSM unlocked Data card or 21 mbps data card is another matter.
Get HUAWEI 7.2 mbps card like E1750/E173 or 21mbps UMG 1831.
I used BSNL 3G for 6 months when they offered unlimited 6 months pack @ rs 4500. Had a horrible experience.
But nowadays their speeds are ok but constant dis connection and some times poor signal inside house in a far off colonies isa issue (main roads -signal ok)
Also BSNL 3G package is as expensive or more expensive than Airtel/Aircel 3G.
I still keep BSNL 3G pre paid sim with a small 3 G data pack for travel to remote interiors. ( all dist HQ all over India have BSNL 3G more so in South. In CDMA all India best network is Reliance Netconnect ,then Photon Plus and the MTS.
Buying propreitory CDMA modem which can not be used with any one elese is madness, (that is why it is sold @ Rs1000)