A total of 16,38,428 candidates have registered for class X examination, while 11,86,306 candidates have registered for class XII examination.
The class X board examination has been reintroduced from this year after the government decided to do away with the Comprehensive and Continuous Evaluation (CCE) adopted earlier.
The exam will be conducted at 4,453 centres across India and 78 centres outside India.
Similarly, for class XII, the exam will be held at 4,138 centres in India and 71 centres abroad.
"The board has made appropriate arrangements with state authorities and local police to ensure trouble free examinations throughout the country," the CBSE official said.
Candidates suffering from diabetes are allowed to carry eatables inside the examination centres.
From this year, CBSE is also allowing candidates with special needs to write their exams using laptops but their device will have to undergo an inspection by the computer teacher at the exam centre and no Internet access will be allowed.
A total of 4,510 and 2,846 differently-abled candidates have registered for class X and XII examinations respectively.