Hello Jahid,

IISC provides admission through 3 channels KVPY, JEE & NEET UG in Bachelor of Science course. Apart from that, you will can apply direct for the same separately .
NEET UG ( securing a minimum of 60% (GN), 54% (OBC-NCL), 30% (SC/ST/PWD)), is the minimum criteria for eligibility for IISC.
For more information, you can go through the official website.

Hope This Helps :)