Actually it's really your choice.
You can get a new PP after the first one is finished and carry both (one with the sticker and one with the blank pages).
Or you could get a new PP and have a new AU sticker put in by the AU consulate/DIAC office.
In the US you can get pages added, I think in India they issue a new PP with the same number and same expiration. Just call Indian consulate to ask them whats recommended.
You can get a new PP after the first one is finished and carry both (one with the sticker and one with the blank pages).
Or you could get a new PP and have a new AU sticker put in by the AU consulate/DIAC office.
In the US you can get pages added, I think in India they issue a new PP with the same number and same expiration. Just call Indian consulate to ask them whats recommended.