I want to leave engineering in 1st year as I am not interested. What can I do?

Find out where your interests is? What kind of work you want to do? Make clear choice and then leave engineering and get started where your passion is. If it is in different department then you have an option for branch change also. But first find your interest otherwise you will keep changing.

You can leave engineering, if you feel uncomfortable pursuing it. It is understandable because B.Tech is not easy to pursue for everyone. You can dropout now and take admission in any other course you wish. There are plethora of courses available in almost every imaginable stream. Look for a course