Hi Sweety!

Even though you have chosen PCB stream without mathematics, you can still go for ISRO. If you are able to get admission into IIST then it paves the way for you to get into ISRO. You just need to clear ISAT entrace exam after 10+2 class. But kinldy note that the entrance exam contains questions related to mathematics, so you definitely need to study maths for clearing the exam. This is the only option as far as I know to get admission into IIST or ISRO.

Thankyou!