At Undergraduate Level you need to answer the JEE Main Examination, to secure admission in NITs, IIITs, GFTIs with a Good Percentile/Rank as well as qualify to appear for the JEE Advanced Examination for IITs.

For more information about JEE Main do follow the link below

https://engineering.careers360.com/exams/jee-main

At the Postgraduate Level, you need to answer GATE for M.Tech/PhD or IIT JAM for M.Sc in IITs/IISc/NITs and Other Government Engineering Institutes.