Under JAA rules you have 14 ATPL exams and you have a total of six sittings to pass them all. Additionally, no single paper can be attempted more than 4 times. Each paper is either passed or failed, there is no middle ground.
If the exams are not all passed within six sittings, or any individual paper is not passed in four attempts, you have to start again and re-take even the exams you have passed.