Hello Savitha. Thanks for contacting Careers360 and we hope we will be able to answer your query. 

The best college in TN that accepts admissions to its undergraduate B.Tech courses is NIT, Trichy. Since, it is among the premier academic institutions in the country, the level of input you should put into your JEE Mains preparation should be quite high.

I would like to direct your attention to this Careers360 article for more information about more colleges:

• https://engineering.careers360.com/colleges/ranking/2017/top-engineering-colleges-in-tamil-nadu-accepting-jee-main-score

Also, please see here:

• http://m.htcampus.com/engineering/colleges-in-tamil-nadu-state-accepting-jee-main-aieee/

Hope this helps you and all the best!