Moral admonitions are not going to stop smoking on the Indian Screens. Plus there is an element of freedom of expression.
The punishment has to be economical. Make all films that have smoking scenes to be an Adult film. That will keep a key demographic out of theaters and put a rein on the "creative" instincts of artists. Wallets are the least common demonitors here, not morality.
Ofcourse stars can do whatever they want in public, including smoking. The health minister has a habit of targeting North Indians, he would hesitate to say that about South Indian stars.