Smart India Hackathon is the flagship Hackathon organised by the Government of India. Widely regarded as the largest Hackathon of its kind in the world, it attracts thousands of students all over the country every year who solve problems ranging from those supplied from corporates and PSUs to government ministries. Details can be accessed via https://www.sih.gov.in/
There is a separate Hardware and Software edition.
This category is only for SIH. For other hackathons visit the hackathon category.