Then, we will have a question after the 3rd year, "I have a low CGPA in IIT, what can I do to get a job in top companies?" or "I have low CGPA in IIT, what can I do to get admission in the top universities in US?"
Were the people who were studying for the last 3 years stupid? And, the teachers teaching you stupid? You reap what you sow! You sowed laziness, laxity, derision of teachers, etc. So, that is what you will reap.
Now coming back to the question: Didn't they tell you the same thing about the board exams? Many students from IIT will attest to this: This is never true. It may seem to be true BEFORE you enter IIT, but once in IIT, you will find it is not true. There are students in my class who are in their fifth year, who never come to class, do not submit assignments and hence, score poorly in their exams. How do they expect me to pass them?
Please come to IIT, if you wish to study. Otherwise, you will find yourself in a similar hole. You can do other things, but becoming an engineer should be your primary goal. You can search for "low CGPA IIT" on quora or google. There is at least one question posted everyday. If your statement were true, then these questions would be false, but they are not. People are worried about their CGPA (marks in IIT).
Anyway, life is never easy. Take it from someone who has been to IIT and US and seen many others who have done similar things. Life is not easy even for the President of US, arguably the most powerful man in the world.
Life is never easy, my friend, it is never easy.