Reservation on competitive basis prescribes proportionate allotment rules and eligibility for reserved allocations in securities issues. Reservation on competitive basis allows issuers to allocate securities from the issue size (excluding promoters' contribution and net public offer) to specified categories-employees, certain non promoter shareholders, and, for IPOs, pre existing business associates-subject to eligibility exclusions. Allocations within each reserved category are made proportionately to applications, subject to prescribed aggregate ceilings, individual employee allotment caps with an under subscription exception, reallocation rules for unsubscribed portions, and spill over provisions from reserved categories to the net public offer.