Students will be eligible to appear at the main/final examination conducted by the institute only after they have successfully completed the coaching process.
Taking oral coaching is like joining a recognized institution and going to college for classes. The institute conduct coaching classes at it’s offices (Head Office/Regional Office/Branches/Chapters). The Institute also accredit colleges and private coaching centers for conducting oral coaching classes i.e. imparting oral coaching. A student may opt to join any one of these classes.
The coaching process involves conduction of teaching classes and examinations at the end of the coaching period. A student will be made eligible to appear at the main examinations only if he qualifies in the end examinations conducted by the oral coaching center that he/she joins.
You can compare it with joining a degree college for being eligible to appear at the university B.Com examination as a regular candidate. The end examinations can be understood as an equivalent of the pre-public that the colleges conduct. Getting through the pre-public (i.e. end exam) here is compulsory.
Taking postal coaching is like joining any correspondence course. A student has to prepare on his own. No teaching classes would be conducted.
The student is supplied with a set of study material in each subject. A set of question papers would also be supplied along with the study material. The total material is divided into parts and the question papers would be such that a student would be able to answer the first set after studying a part of the material. The answers to the question papers provided with the study material are to be periodically submitted within the prescribed time limits.
The submitted answer papers would be evaluated and returned to the students. A student has to qualify in the required number of papers to be eligible for appearing at the main examination.
This would amount to doing a correspondence course and attending the pre-public examination at home.
The time limits prescribed are for getting eligibility to appear for the main examination conducted during a specific term. If the papers are submitted beyond the time limit for a specific examination, the student would be eligible to appear at the subsequent examination.