GATE

Many universities conduct their own entrance exam also to fill the rest seats. But I am not sure that you will get admission because of your UG degree.

Hello Vamsi, GATE (Graduate aptitude test in Engineering) is an all india level examination for the admission into post graduate courses in Engineering such as ME / M.Tech. It is conducted by the IITs and is used for the admission into PG engineering programs in the same as well as other institutions.
You need to have completed a Bachelors degree to be eligible for this exam. If you have a B.Sc. Then you can appear once you complete an
M.Sc only.

Hello Aakash, For GATE you need four year's Bachelors course. If your B.Sc. Is of four years then you are eligible.
I am attaching a link that will give you all the required information.
http://www.gate.iitg.ac.in/?page_id=49.

Ideally, you should start the preparation in third year. You can take coaching from various institutes. You can also get online coaching for it.

Hi, IIT Madras is known as one of the best college.if you wish to go abroad for higher studies after M.tech, I would strongly recommend you to join IIT Madras. It has a really great brand name among IITs across the world and the chemical engineering department here has professors known worldwide in their field.If you are aiming for placements, I won't recommend you to join IIT Madras.