Hello Aspirant.

Hope you are doing well.

No, there is no such guideline regarding this that you'll have to do your 9th and 10th schooling from the same school according to the CBSE Board. There is no such guideline if you want to change your school after 9th from one CBSE or any other board to other school of the same board you can change it but you'll have to fulfill the eligibility criteria for the admission because every institution have different rules and regulations regarding the admission process.

GOOD LUCK, STAY MOTIVATED AND HOPE THIS HELPS.

Thankyou.