In Prospectus it is written that " Provided that a candidate who has appeared in the subjects of a group, for which he was required to enrol & has secured 60 percent or more marks in any subject & a minimum of 25 percent marks in each of the remaining subjects of the group, but has failed in the group, shall be exempted from that or those subjects in which he secured 60 percent or more marks, in any subsequent examination on submission of an application in this behalf on or before the last date of enrolment for the examination in which he intends to appear."
So to get exemption u have to get minimum 25 percent marks in other subjects.