Government quota
TAMIL_NADU_GOVERNMENT_QUOTA_RANK
1,250
verified R1–R3 rows
63–64 colleges · 7 categories · 4 seat groups
Moderate movement overall, with a wider R2→R3 tail even though the median absolute movement fell.
AdmiScan Data Moat #8
Tamil Nadu NEET 2025 MBBS cutoff volatility: three quota rank systems, three different patterns
AdmiScan analysed 2,103 verified Round 1–3 cutoff rows, formed 1,374 exact adjacent-round comparisons, and separately matched 687 exact R1→R3 keys. Government quota, government-school 7.5% reservation and management quota ranks are reported separately because they belong to different ranking populations.
The headline finding
The government-school 7.5% series was the most stable in the published data, government-quota movement was moderate with meaningful tail risk, and the smaller management/minority/NRI comparison set was substantially more volatile—especially from Round 2 to Round 3. These are historical descriptions, not 2026 predictions.
Three independent rank populations
Government-school 7.5% reservation
TAMIL_NADU_GOVERNMENT_SCHOOL_7_5_RANK
687
verified R1–R3 rows
63–64 colleges · 7 categories · 1 seat group
Most exact keys were unchanged across adjacent rounds; isolated changes remain visible in the tail.
Management, minority and NRI quota
TAMIL_NADU_MANAGEMENT_QUOTA_RANK
166
verified R1–R3 rows
26–27 colleges · 8 categories · 4 seat groups
The smallest comparison population had the largest median and p90 absolute movement, especially from R2→R3.
Round-level volatility
“Comparable” means the exact same rank metric, college, MBBS programme, seat group and category existed in both adjacent rounds. A higher closing-rank number indicates that the observed cutoff extended further down that ranking list.
| Rank system | Rounds | Comparable | Unchanged | Median abs. | P90 abs. | Median abs. % | P90 abs. % |
|---|---|---|---|---|---|---|---|
| Government quota | R1 → R2 | 410 | 25.4% | 158 | 934 | 3.13% | 22.70% |
| Government quota | R2 → R3 | 408 | 39.5% | 82 | 1,355 | 3.15% | 21.26% |
| Government-school 7.5% | R1 → R2 | 227 | 97.4% | 0 | 0 | 0.00% | 0.00% |
| Government-school 7.5% | R2 → R3 | 227 | 89.4% | 0 | 8 | 0.00% | 1.60% |
| Management / minority / NRI | R1 → R2 | 51 | 19.6% | 783 | 4,894 | 11.46% | 32.93% |
| Management / minority / NRI | R2 → R3 | 51 | 29.4% | 2,671 | 15,010 | 19.27% | 245.30% |
What changed from Round 1 to Round 3?
This longer-window view uses the same exact-key matching rule as the adjacent-round study, but measures signed movement from R1 directly to R3. A positive signed delta means the closing-rank number increased within that same Tamil Nadu rank system; it does not make raw ranks comparable across systems.
| Rank system | Comparable | Median signed delta | Median signed % | Relaxed | Unchanged | Tightened |
|---|---|---|---|---|---|---|
| Government quota | 409 | +461 | +9.92% | 338 | 67 | 4 |
| Government-school 7.5% | 227 | 0 | 0.00% | 28 | 199 | 0 |
| Management / minority / NRI | 51 | +5,820 | +51.15% | 37 | 11 | 3 |
The 7.5% series has a median signed movement of 0.00%, but that does not mean every key was unchanged: 28 of 227 exact R1→R3 keys relaxed while 199 were unchanged.
Selected R1→R3 seat-pool signals
These segments remain within their own rank system. Smaller samples are shown with their sample size rather than promoted as statewide conclusions.
| Rank system | Segment | Comparable | Colleges | Median signed % | Context |
|---|---|---|---|---|---|
| Government quota | Government colleges | 228 | 36 | +12.96% | 182 relaxed · 44 unchanged · 2 tightened |
| Government quota | Self-financing colleges | 141 | 22 | +7.49% | 121 relaxed · 18 unchanged · 2 tightened |
| Government quota | Private universities | 27 | 4 | +12.62% | 27 relaxed · 0 unchanged · 0 tightened |
| Government-school 7.5% | Government colleges | 134 | 36 | 0.00% | 1 relaxed · 133 unchanged · 0 tightened |
| Government-school 7.5% | Self-financing colleges | 76 | 22 | 0.00% | 17 relaxed · 59 unchanged · 0 tightened |
| Management quota | Self-financing colleges | 14 | 14 | +157.68% | 14 relaxed · small segment, so read with sample size |
Government quota
R1→R2 had a median absolute movement of 158 across 410 keys. R2→R3 had a lower median of 82, but its p90 increased to 1,355—evidence that the tail remained important.
Government-school 7.5%
The median absolute movement was zero in both transitions. Exactly 221 of 227 R1→R2 keys and 203 of 227 R2→R3 keys were unchanged, but isolated category-college movements still occurred.
Management, minority and NRI
Among 51 comparable keys per transition, median absolute movement rose from 783 in R1→R2 to 2,671 in R2→R3. The smaller sample and mixed seat groups make segment context essential.
Category and seat-group signals
These selected signals show why one statewide median is insufficient. Small samples are displayed rather than presented as broad conclusions.
| System | Rounds | Category / group | Comparable | Median abs. | P90 abs. | Context |
|---|---|---|---|---|---|---|
| Government quota | R1 → R2 | ST | 58 | 593 | 4,083 | Largest government-quota median in this transition |
| Government quota | R2 → R3 | SC | 64 | 968 | 2,028 | Largest government-quota median in this transition |
| Government-school 7.5% | R1 → R2 | BCM | 19 | 0 | 0 | One isolated maximum movement of 160 ranks |
| Government-school 7.5% | R2 → R3 | BC | 63 | 0 | 38 | Eight of 63 exact keys changed |
| Management quota | R1 → R2 | Management quota | 18 | 413 | 1,034 | All 18 comparable keys changed |
| Management quota | R2 → R3 | Management quota | 18 | 9,526 | 16,518 | All 18 comparable keys changed |
| Management quota | R2 → R3 | NRI | 17 | 0 | 2,094 | 11 of 17 exact keys were unchanged |
Exact-key examples
Examples retain the quota-rank system, college and category. They illustrate the distribution and should not be read as forecasts for the same college.
| System | Rounds | College | Category | From | To | Movement |
|---|---|---|---|---|---|---|
| Government | R1 → R2 | Coimbatore Medical College | ST | 5,183 | 12,563 | +7,380 |
| Government | R2 → R3 | Kanyakumari Medical Mission Research Center | ST | 15,806 | 22,014 | +6,208 |
| Government-school 7.5% | R1 → R2 | Thanjavur Medical College | BCM | 9 | 169 | +160 |
| Government-school 7.5% | R2 → R3 | Dhanalakshmi Srinivasan Medical College | SC | 645 | 726 | +81 |
| Management / minority | R1 → R2 | Christian Medical College, Vellore | Minority network | 5,606 | 26,738 | +21,132 |
| Management | R2 → R3 | Kanyakumari Medical Mission Research Center | Management quota | 6,351 | 23,520 | +17,169 |
Methodology and limitations
- • Only verified Tamil Nadu MBBS rows from R1, R2 and R3 of 2025 are included.
- • Comparisons require an exact rank metric, college code, programme, seat group and category match.
- • All three rank systems passed the exact-key duplicate check with zero duplicate keys.
- • Non-positive published ranks are excluded from movement calculations.
- • Median describes the middle; p90 exposes the wider movement tail.
- • The R1→R3 section uses signed deltas; adjacent-round volatility uses absolute-movement medians and p90s.
- • Stray and special-stray rounds are excluded and reserved for a separate study.
Source authority: Selection Committee, Directorate of Medical Education and Research, Tamil Nadu. This page is a dated 2025 evidence snapshot, not a live counselling feed.
Frequently asked questions
Why are the three Tamil Nadu rank systems analysed separately?
They represent different ranking populations. A government-quota rank, government-school 7.5% rank and management-quota rank are not interchangeable, so combining them would create misleading medians and percentiles.
Does an unchanged closing rank mean nothing changed in counselling?
No. It means the published closing rank for that exact college, programme, seat group and category matched between the two rounds. Seat availability, allotment counts and candidate behaviour may still have changed.
Why can percentage movement look extremely large?
Percentage movement is sensitive to a small starting rank. For example, moving from rank 9 to 169 is only 160 ranks but produces a very large percentage. Absolute rank movement and sample size should be read alongside percentages.
Can Tamil Nadu 2025 volatility predict 2026 cutoffs?
No. This is a dated historical study. Seat matrices, rules and applicant behaviour can change, so the findings provide context rather than an admission forecast or guarantee.
Use the evidence with your own profile
Historical volatility helps explain uncertainty, but your category, quota and preferences determine which colleges are relevant. Use the Tamil Nadu NEET audit for a personalised decision review.