Hello aspirant

Yes isi exam is a little harder to crack but don't worry with proper hardwork and practice you will be able to score well in the exam and don't be anxious every other entrance exam has a certain level of difficulty to choose the best among the rest.

To prepare for the exam you should know the exam pattern throughly which is as follows:-  t here are two parts of the entrance examination i.e. part-1 and part-2. Part-1: the entrance exam will be of objective nature which will comprise of the multiple-choice questions. part-2: Exam will be of descriptive nature comprising of short answer type questions. In addition to that, there will be some questions from reasoning also in the entrance test.

You should practice as much as you can and check previous years question papers to get a better idea. Use this link for the same:-

https://www.isical.ac.in/~admission/Syllabus-And-QP.html

The cut-off of ISI exam is every year. For multiple choice questions sections, the cut off usually remains around 60 to 75 out of 120 based on the difficulty of the questions Whereas the cutoffs for subjective type questions remains from 35-50 out of 80.

Hope this helps