A horizontal line of high signal intensity seen not extending to superior or inferior articular surface of posterior horn of medial meniscus but extend to meniscocapsular end...is this described as tear?

Probably not. MRI readings are never exact. This one is vague and indicates possible inside damage to the meniscus. When it does not extend to the superior or inferior articular surface then it is not a standard meniscal tear which does extend to one or both of those surfaces. This condition might be causing you problems, but arthroscopic surgery is not truly indicated unless your knee is locking. Good luck!