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

First, please note that the IITs are the premier academic institutions in the country. The admissions to its undergraduate B. Tech courses take place only through the JEE Advanced window. So, obviously the level of input you should put into your JEE Advanced preparation should be quite high. 

I would like to direct your attention to this Careers360 article for more information about the cutoffs for IIT Roorkee through JEE Advanced:

• https://engineering.careers360.com/articles/jee-advanced-cutoff-for-iit-roorkee

Hope this helps you and all the best!