Stamp duty on under prefential allotment

Hello,

Under the companies act 2013, For payment of stamp duty on share certificate after allotment under preferential issue listed company

pls suggest. Following.

1) franking on share certificate still exit ??

2) Is it ok to pay stamp duty by generating eSBTR challan and making payment on any of IDBI , punjab national bank etc ??

3) What is the other offline mode for payment of stamp duty ??

4)Can stamp duty after allotment is paid when in principle of listing approval is pending from BSE ??