In most other recruitment processes interview marks are a fraction of the written exam market and there are no minimum qualifying marks for interview (even for the Civil Services Exam popularly known as IAS Exam).
SSB Interviews are at an entirely different level. Here a candidate is assessed by a board of three assessors for a period of 5 days. A candidate has to meet the qualifying standards of each of the three assessors.
To qualify SSB candidate should have developed personality over the entire academic life or he requires prolonged efforts to achieve a desirable level.