How much a bid costs, and which investor category it puts you in.
Retail Individual Investor — applications up to the retail ceiling. This is the only category where allotment is a lottery when oversubscribed, which is why the allotment probability calculator applies to it.
Small NII (sNII) — above the retail ceiling and up to the sNII ceiling. Big NII (bNII) — above that. Allotment in the NII categories is proportionate or by draw of lots, and the odds behave differently from retail.
Applications above the UPI mandate limit cannot use the UPI route and must go through ASBA at your bank.
Educational tool, not advice. Figures are arithmetic on the numbers you enter. Nothing here predicts an outcome or recommends an investment. Verify against your broker and the official registrar before acting.