hi,

you can join iiser through jee main advance score or through kvpy exam scheme or SCB (Aptitude Test) Channel . there is bs -ms dual degree courses available after 10+2 passed students. after the passing of bs-ms you can opted for phd, most of the students do phd course and work as a scientist in research and development center in reputed organization. see getting admission in iiser is enough to start a journey for a wonderful career.