If our India is clean, hygienic it will be a country free from diseases. Garbage attracts mosquitoes, pests, rats, and other disease carriers. They spread diseases like malaria, dengue, yellow fever, etc. These diseases are communicable diseases, so spread form one person to another. So, a cleaner India, would definitely be a healthier India.
Another benefit we'll get is increased tourism. Tourists admire the beauty but hate the dirtiness in India. So it will also increase tourism.