x Catalyst Lab | Computational Audit of JoSAA Allocation
Mechanism Design & Empirical Audit Harness

Computational Audit of JoSAA Allocation Rules

We formalize and audit the central pillars of India's Joint Seat Allocation Authority: sequential multi-round clearing under Freeze/Float/Slide, and legally mandated vertical reservation interleaving (Merit-First OPEN seats vs. Category Quotas).

Baseline Algorithm
Student-Proposing DA
Reservation Framework
Sönmez-Yenmez Interleaved
Dynamic Guarantee
Weakly Strategy-Proof
DSIC Empirical Audit
0.00% Gain (600 Tests)

⚡ Interactive Simulator: Full-Rank Allocation & Regret

Calibrated from Ranks 1 to 25,000+ across top IITs, NITs, and lower-tier branches.

Live Engine
Try 45, 1200, 5400, 11000, or 18000
Choice #1 (Dream Choice)
Choice #2 (Realistic Target)
Choice #3 (Safety Option)

Module 1: Dynamic Round Simulator & Vacancy Chains

Round 1 Allocation
Applicant 001 (Rank 1) → IIT Bombay CSE
Applicant 002 (Rank 2) → IIT Delhi CSE
Round 2 Allocation (After Shocks)
Applicant 001 → Withdrawn (Seat Released)
Applicant 002 → IIT Bombay CSE (Upgraded via Float)
Audit Result: Floating captured the vacancy cascade. Candidate 002 strictly benefited from multi-round flexibility.

Module 2: Vertical Reservation Interleaving Audit

Under the Supreme Court mandate (Indra Sawhney / Sönmez-Yenmez), reserved category candidates must first consume OPEN merit capacity if their score qualifies, reserving category quotas for subsequent candidates.

Rank 1: Candidate A
Category: OBC
Rank 2: Candidate B
Category: OPEN
Rank 3: Candidate C
Category: OBC
Available Capacity (IITB CSE): 1 OPEN Seat, 1 OBC Seat
OPEN Merit Seat (Cap: 1)
Candidate A (Rank 1, OBC)
Consumed by Rank 1 via CRL merit order.
OBC Category Seat (Cap: 1)
Candidate C (Rank 3, OBC)
Preserved for next eligible category candidate.
Outcome: Candidate B (OPEN, Rank 2) is displaced because Candidate A claimed the OPEN seat on pure merit, leaving the OBC quota available for Candidate C.