Anna University

Hello Anu Sri,
The admission into IITs for any course is based on the JEE advanced exam only. So you need to clear JEE main and then JEE advanced with a good rank so that you can get a seat for biotechnology in IIT.
To get admission at Anna University, your board exam marks alone are considered and there is no entrance exam. Your cut off in PCB out of 200 is considered.

You can get admission in Anna University by using TNEA. There is also criteria for other state students to take admission.
For Jadavpur, WBJEE needs to be given and Djibouti takes admission through JEE Mains.
See this link for Anna University:
https://www.google.co.in/url?sa=t&source=web&rct=j&url=https://www.quora.com/How-can-non-Tamil-Nadu-state-students-apply-for-Anna-University-and-affiliated-universities-Whats-the-eligibility-criteria&ved=0ahUKEwig_eKt4bjXAhXGs48KHUQ1BNUQFggtMAI&usg=AOvVaw1qpIYdXdqV7RgRCuE-o-_p

He may change, but he will need to start from the beginning. He will need to reapply for the respective entrance exam and have to start the course from first year.

You can apply online through the web portals once they are made available.
Selection is mainly through single-window counselling system based on your High school (i.e. 12th or junior college according to your state) marks, when studying under class 10+2 system in India. They see your PCM mark aggregate (generally called CUT-OFF mark in TN) out of 100.

Hi, your IELTS score is good. For MS in engineering, the cut offs are bit on the higher side. But, you should be able to get good options in Canada. Also, most universities will expect an explanation for the backlogs. So, be prepared for that. Are you planning to give your GRE?