Hello,if you are from cbse board then your compartment exams will be organised by the central Board of secondary education.These examinations are held for those students who will not clear the class 10th or class 12th exam in one or two subjects.Cbse has a provision for providing three chances to clear the compartment exam.If you are not able to clear your exams or secure good grades even after three attempts you are considered failed .Both private and regular students can apply for cbse compartment examination.For class 10th compartment examinations will begin from 25th August and end on 8th of September whereas for class 12th students examinations will begin from 25th August and end on 15th September.The application form is different for every individual hailing from different categories.If you are a regular student who appeared in class 12th examinations during the month of April/June and their result is declared compartment are eligible to appear for compartment examinations.if you have failed in more than one subject then you will have to appear for two subjects in which you faced compartment.If you were not able to clear one subject you can appear for compartment examinations under the improvement of performance category.Regular students may habe to go to the school and enquire about compartment examinations whereas private students can easily apply through the cbse site .

This is the criteria i have told you for the cbse board.If you are from any other board like hp board,up board or Maharashtra board,let me know and i would enlighten you with the knowledge i have regarding the compartment examinations held by these boards