No offense friend, but the fact is if at all a nuke war is occured,
for a sqmt of pakistan 0.25 sqmts of Indian territory is lost.
Provided India uses aircrafts by exploding high yield devices(pakistans aircrafts will have more threat than indian ones and india has many aircrafts) , the damage will be more to pakistan.
But since the population density is high in India the no. of deaths may increase but the percentage will be less when compared to pakistan.
If 50 % of pakistan is bashed, 20% of India will be gone.
Same way 50% of India is gone means 35% of china will be gone.
(If US enters with a threat probability if china nukes India, Most of China would lose.).
No offense .