Hello Aspirant ,

To get admission in IIT (Indian Institutes of Technology ) you have to first pass JEE Mains exam (which happens 4 times in a year and you can attempt it for 3 consecutive years starting from the year of passing class 12 ) and then appear for JEE Advanced Examination which is conducted only once a year , so you can only fill the exam form for IIT one time in a year . However you can attempt 2 JEE Advanced in 2  consecutive years starting from the year of passing class 12 .

For more details about JEE Advanced visit :

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

Hope this helps.