Both IIT Kanpur and IIT Delhi are premiere engineering institutes offering top-quality education. However, the curriculum at IIT Kanpur has a theoretical approach and is taught by better professors than at IIT Delhi. The curriculum at IIT Delhi has a practical approach.
Once you have decided on the Institute, you need to decide the program you will be pursuing; B.Tech or Dual degree. For someone interested in research, you can take BTech in IIT Kanpur and then go for MS from top foreign universities like Stanford or MIT. But if you are looking for a high-paying job, a BTech from IIT Kanpur or a dual degree from IIT Delhi would be more than enough to fetch you good packages.