Hello sir,
There isn't any interview conducted to get admission in Korukonda Sainik school.The admission is based on merit in entrance exam and medical test.There isn't any cut off for medical test, your son must be medically fit and meet the required medical standards.Even if he pass his medical test the merit list is prepared based on the performance of all candidates appeared in exam.So a candidate must have good score in entrance exam and meet the medical standards to have a good chances of getting admission.
Here is the prospectus.Kindly go through it and the medical standards given by them
Korukonda sainik school Prospectus 2020-21 (http://www.sainikschoolkorukonda.org/wp-content/uploads/2019/08/prospectus-2020-21.pdf)
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