The registrar to the issue is a SEBI-registered intermediary appointed by the issuer to handle the operational backbone of the IPO: collecting bids from the exchange, validating PAN and demat details, finalising the basis of allotment, processing refunds, and crediting allotted shares to demat accounts.
India has roughly half a dozen large IPO registrars — Link Intime India, KFin Technologies (formerly Karvy Fintech), Bigshare Services, Cameo Corporate Services, Skyline Financial Services, and Mas Services. The registrar's website is where allotment status is checked using PAN, application number, or DP ID after the basis of allotment is finalised.
Most allotment-status checker tools on aggregator sites — including BasicFintech — query the registrar's public allotment portal under the hood. The registrar is also the contact point for any post-listing operational issues like missing demat credits or delayed refunds.