hi,
I assume you are asking for Indian statistical institute B.math or b. state entrance exam. see the questions are based on 12th maths and aptitude. so you may practice from jee main or any other standard exam math book let. you would find some free lectures on you tube as well.
another option is sourav sir classes , this institution provides coaching for ISI entrance test. you may look for it.
Application | Admit Card | Answer Key | Result | Counselling | Dates | Syllabus
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile