India has faraway bases - like in Nicobar islands.
Depends on the yield of the nukes. According to reports pak's nukes are of no more than 50kT. For that yield, it would require at least 2000 nukes to annihilate india completely - economically and militarily (FAS nuclear damage estimates).
Of course, the goal of pakistan should not be to "destroy" india but just maintain enough deterrence so that peace can be ensured.