Hello Dear,

IISER-AT stands for Indian Institutes of Science Education and Research Aptitude Test is a national-level examination which is conducted for admission in the five-year BS-MS dual degree programme offered at Indian Institutes of Science Education and Research (IISERs). The official date for IISER Aptitude Test 2021 will be released soon, and the online registration is expected to begin in March.

For more information related to the registration process you can visit the link below:

https://engineering.careers360.com/articles/iiser-admission

Good Luck