Stamp duty on issueof share certificate in mumbai

Hi,

I have some queries about issue of share certificates in maharashtra.

1. Can stamp duty be paid on share certificate before approval of allotment? since as per stamp act, stamp duty has to be paid on or before execution.

2. What is the procedure for online payment of stamp duty on share certificate in mumbai, is it through GRAS, if yes, pl provide detailed procedure.

3. Is Stamp duty payable on total consideration i.e. nominal value + premium, if any?

Pl clerify my doubts.