Kanpur is an important rail junction in northern India so chances are that there is a direct train from you city to Kanpur. Please try to get a ticket to the Kanpur Central (Station code CNB) station. The Delhi-Kanpur route is particularly well served. However, tickets might be difficult to obtain in short notice. Some of the better options are the following.
The southern cities are not that well connected to Kanpur. In case of difficulty in getting a direct train to Kanpur, consider taking a ticket to Jhansi instead. One can then reach Kanpur either by bus or local trains.
There are good connecting flights from Delhi, Mumbai, Banglore, Calcutta to Lucknow. IIT Kanpur is about 90Kms from Lucknow
This is the least preferred way to reach Kanpur. If you plan to take a flight consider Lucknow instead.
Taxis and auto-rikshaws are available from Kanpur central station. From Lucknow airport one can hire a pre-paid taxi.