I think this is wrong thing...
It should be like this,
(1) CASE A:
If a person take unlimited connection then it costs 900+tax... no matter how much he download... connection speed is 256kbps for unlmtd, suppose he download to max 20hrs/day and 30days a month, then taking downloading 100mb/hr, the TOTAL will be around 60GB/MONTH
Still he has to pay only 900+tax..... no extra charge
(2) CASE B:
If a person take limited plan like Home 250, home 500... then there is limit for uploading/downloading.... and the bill come with addition....
So in this case if downloading is big then bill will be HUGE, like in this case it is assumed to be around 1Lakh
SO FOR THE LIMITED PLAN, THERE SHOULD BE BILLING LIKE THIS.....
FOR HOME500.. MINIMUM 500Rs+EXTRA CHARGE AS PER DOWNLOAD, BUT NOT EXCEED 900MARK... THAT IS FOR UNLIMITED USERS.. So max should be 900+tax or may be 1000-1200 fixed, not like 60000, 90000, or Lakh....
There is one difference now, from 1 January there is speed difference for unlimited and limited users.... like home500 and 256 provided upto 2Mbps speed while unltd users with 256Kbps..... otherwise it is same....