In Airtel - DBR, Migration and Standard means the same thing. It means there is no upfront charges and you will be charged daily burn rate. Unfortunately the app does not have a place to display the dbr and monthly amount yet. I hope one of the next updated fix it.
App currently displays only upfront charge. If they show monthly rate then 6 month topup subscribers will be shown 1/6 of the amount that will be deducted and could deactivate their account. Current option is most reasonable according to me. BTW monthly rates are still displayed under subscribed topups list. Example Hollywood SD sale will be shown as Rs.40 and not Rs.4 in subscribed list.
In this case you will only lose Rs.2 and you can deactivate it next day itself.