To get admission into Indian Institute of Information Technology, there are three possible ways:

1. Give JEE Main and get a competing rank, usually under 1000 as the competition for IIITH through JEE Main is intense.

2. Give UGEEE, which IIIT Hyderabad conducts itself, and after clearing it give an interview and perform well in it. Usually the interviews are tougher than UGEEE itself.

3. Be a person who has made his/her name or represented India in a big Olympiad like IOI as IIITH gives direct admission to these students.

Hope I have answered your question. All the best!