Hello,

There is no upper limit as such mentioned by the officials when it comes to fulfilling the eligibility criteria of ISI Entrance Exam, the eligibility criteria for the undergraduate courses offered are as follows-

• BStat: Passed 10+2 from a recognized board with English, and Mathematics
• BMath: Passed 10+2 from a recognized board with English, and Mathematics

You can check out the FAQs section at https://www.isical.ac.in/~admission/Documents/IsiAdmission2020/Application-FAQs-2020.pdf to know more details pertaining this, hence as long as you fulfill the eligibility criteria you can appear for the exam,

you can also visit the official website at https://www.isical.ac.in/content/ug-admission to know more details about the entrance exams, and other essential details,