Hello,

To get admission in IIT you have to give JEE Mains exam. Once you have given the exam , if you are among the top 2, 24,000 then you would be qualified or eligible to appear for JEE Advanced. 

JEE advance for the year 2019 will be conducted on May, 27 and it will be a computer-based exam to be held in two different sessions for Paper 1 & 2 for admissions to the undergraduate engineering programmes at the IITs. It is mandatory to attempt both Paper 1 and 2.

for more details: https://engineering.careers360.com/articles/jee-advanced