TNEA

Hello Naveen,
There is no comparison between IITM and any other college as it is of high standards. You need to clear JEE Advanced for IITs. To know about the colleges which you can get, you may refer:
https://info.tnea.ac.in/tinfo/index.php
You cannot get the top ranking colleges like CEG and MIT but you can try for other affiliated colleges.

Yes, after completing your graduation you can join M.Tech biotechnology. As after graduation you will be able to study M. Tech. So, you can try to get admission in a good college.

As per your marks, you might get a seat in TN counseling. You can try to get admission there as your admission will also depends on rank so, you may get a seat there.

Yes! You can apply for TNEA via Other State Quota. Wishing you best of luck.

Visit this link for your queries!
http://cutoff.annauniversitycounselling.com/tnea/cutoff_search Wish you best of luck.

Yes! You can apply for TNEA through Other State Quota. Best of Luck.

You can Defibmnately get seat in Anna University CEG campus for ECE Branch. BC category has a cut off of 180 matks last year so you will definitely get seat. You can also get seat in PSG. You have both the options. Best of luck for your future and if there's any query, feel free to ask.

Please check for your eligibility to apply for the TNEA exam from the criteria mentioned at the link provided below:
https://www.shiksha.com/university/anna-university/exams/tnea.