Section 63(5)(b) in The Border Security Force Rules, 1969
(b)be informed that, upon his making a written request to his Commandant not less than twenty four hours before his trial requiring the attendance at his trial of a witness (other than a witness for the prosecution) whom he desires to call in his defence (such witness to be named by him), reasonable steps will be taken in accordance with these rules to procure the attendance of any such witness at his trial.