Hey,

You can apply for IISER aptitude test by filling the application form online on the official site of the college,

To apply for IISER Aptitude test the student should fulfill the eligibility criteria which is mandatory  like:

• For KVPY the candidate is required to have a KVPY fellowsjip.
• JEE Advanced the candidate should have  valid rank and score in Jee advanced as prescribed by official authorities.
• For SCB Candidates can apply through this channel. It is mandatory for the candidate applying through this channel to appear in IISER aptitude test.

For more details visit the link below:

https://engineering.careers360.com/exams/iiser-aptitude-test

I hope this helps.

All the best!