It all depends on which stream you want to opt in your 11th standard - Science or Humanities? In the Southern belt where the respective state Governments conduct their own Common Entrance tests for Engineering and Medicine/Agriculture for admission into graduation courses i.e Engineering medical course, people very often prefer to the State Board Examination Viz., Intermediate. States like Karnataka, Andhra Pradesh, Tamil Nadu and Telangana as the entry through the Common Entrance Test for Engineering and Medicine is little bit easier than the JEE and AIIMS entrance tests conducted by CBSE.
Now the scenario is changed and the NEET examination for MBBS was made common to all and the examination would be based on CBSE syllabus at all India level. The admission in Engineering and Architecture in IITs/NITs/IIITs would be based on CBSE syllubus only through JEE Advanced and Mains examination. So, it is always better if you opt for CBSE for any stream whether Science or Humanities. Even if you opt for Humanities also, it would be helpful to excel in the competitive examinations conducted by UPSC and SSC. The knowledge acquired from the NCERT books would be more helpful as compared to the State Board syllabus in various competitive examinations.