Respected sir,

For admission to IIIT-H, you need to get at-least 60% combined in Physics, Chemistry and Maths in your 12th standard.

If your board provides a combined mark-sheet for class 11th and 12th, then you have to get at-least 60% in 11th Physics, Chemistry, Maths and 12th Physics, Chemistry and Maths.

There is no minimum cutoff for marks in Mains. But to surely get a seat in IIIT-H, try to score at-least 255 if you want CSE.

There are many criterion to get admission to IIITHyd.So go through websites of the institute.If your only path is through JEE main,you must score decent marks viz around 100 in each of the three subjects.It is worth mentioning that IIIT Hyd is one of the sought after institutes so far CSE is concerned.DTU & NSIT are also very renowned institutes besides IIT/NIT.

There are also other exams like SAT for NRIs and ICO for extremely talented people.

You can get admission in both ways i.e. they conduct their own exam and also have allotted specific seats filled through jee mains

Procedure through jee main is 

• Application via our admissions portal.
• Reporting your marks in JEE (Main).
• Obtaining a minimum of 60% marks in Maths, Physics and Chemistry in Class XII. 

for more information u can visit the link 

https://www.iiit.ac.in/admissions/undergraduate/jee-mains/

If u want to get direct admission u have to write a exam which is to be conducted on April 18

u can apply before march 26 2018 for 2018-19 admissions

I will beroviding the link for more info

https://www.iiit.ac.in/admissions/undergraduate/ugee-mode/

IIIT Hyderabad Eligibility :JEE eligibility criteria apply to all the IIITs for admissions to their undergraduate programs. Based upon their score and rank in the JEE Advanced exam, shortlisted candidates are called for counseling.