In a Central Autonomous body which follows all Central Government rules, a Deputy Director (PB3 GP-6600) was promoted on ad-hoc basis three years ago to the post of Joint Director (PB3 GP-7600), without a DPC. If a DPC sits this year after 3 years, can his promotion be regularized from the date of his ad-hoc promotion, when the promotion will be considered after preparing year-wise panel for the years when there was no DPC. If possible, kindly inform under which rule or which DOPT OM clarifies this position.