Hey there!

Honestly, the board doesn't matter but grades in the selected stream does when one tries to seek and admission in higher degrees.

As  far as the difference between CBSE and ISC is concerned, the difference nullifies at the time of admission via entrance or interview where the selection is done on the basis of a person's knowledge about the selected stream rather than board one chose earlier.

When one moves to higher studies with these subjects, do check for the career opportunities, internships offered and the jobs that are associated with these streams. Different colleges offer different opportunities and placements. Look well for them.

Good Luck!