JoSAA seat matrix: categories, quotas, seat pools

What the seat matrix is

The JoSAA seat matrix is the authoritative ledger of how many engineering seats exist and who they are reserved for. Before each counselling year begins, JoSAA publishes the full matrix: every institute, every branch, every category, every quota, every seat pool. During the counselling rounds, JoSAA allocates seats out of this matrix — one cell of it at a time — subject to eligibility, submitted choices and the schedule; some candidates can remain unallocated and vacancies can remain.

On RankMatrix, the full matrix is browsable at Seat Matrix.

The five axes you need to understand

Every seat is described by five attributes. Your JoSAA preference list is effectively a set of filters on these:

• Institute — which IIT, NIT, IIIT, or GFTI.
• Branch — CSE, ECE, ME, CE, and so on. Each institute offers a specific menu of branches.
• Category — Open, OBC-NCL, SC, ST, EWS, plus PwD sub-categories.
• Quota — the exact published code. Stored rows include AI, HS, OS, GO, LA, JK and AP; check eligibility in the official rules.
• Seat pool — Gender-Neutral or Female-only.

Every cutoff number JoSAA publishes is pinned to a specific combination of these five axes. Read the cutoff against the combination that will actually apply to you.

Categories, in detail

• Open — the general merit category. Any candidate can be considered against Open cutoffs; reserved-category candidates can also be considered here and will be allocated an Open seat if their rank is good enough.
• OBC-NCL — Other Backward Classes, Non-Creamy Layer. Central government OBC list; a valid non-creamy-layer certificate is required at reporting.
• SC — Scheduled Castes.
• ST — Scheduled Tribes.
• Check the programme-specific category and seat-pool counts in the official matrix; the note above links to the governing rules.
• PwD — Persons with Disabilities. This is a sub-reservation within each of the above categories — there is no separate PwD-only seat pool outside the main categories.

JoSAA considers eligible programme sections in the prescribed allocation sequence. If you are OBC-NCL and your rank is also good enough to get an Open seat, you may be allocated the Open seat instead.

Quota, in detail

HS — Home State

Use the state-code eligibility rule in the official-source note above, including its exceptions.

OS — Other State

Other State eligibility follows the institute-specific rules. Do not infer a universal split or cutoff relationship from this label.

AI — All India (IITs, IIITs, GFTIs)

No state split. Every candidate competes in the same pool regardless of domicile. IITs, IIITs, and most GFTIs use AI quota.

Seat pool, in detail

Gender-Neutral

The main seat pool. Open to any candidate regardless of gender. Most of the seat matrix is Gender-Neutral.

Female-only

This pool can include supernumerary seats. Eligible female candidates can be considered for both pools under the applicable rules. Read the actual programme counts; do not assume every Female-only seat is additional or that one pool always has a larger closing rank.

How to read a seat matrix row

A row records seats for one year, institute, programme, category, quota and pool. It is a stored count, not live vacancies or a forecast of admission.

The change view subtracts the previous stored year for that same slice. A missing previous-year row is treated as zero by the backend, so a positive change is not proof that seats were added. Verify the source before interpreting it.

Historical cutoffs describe allocated ranks. Compare the same rank list and allocation slice; seat counts alone do not establish whether a rank will receive an offer.

Planning your choice list using the matrix

• Start with the college predictor to get a rank-based shortlist.
• For each shortlisted institute-branch, open the Seat Matrix and check seat count in your category + quota + pool.
• Check all category, PwD and seat-pool rows for which you are eligible.
• Seat count helps you understand the available options, but your final choice order should reflect your preferences rather than an assumed allocation probability.

Common questions

What is the JoSAA seat matrix?

The seat matrix is the official count, published by JoSAA before counselling begins, of how many seats each participating institute offers in each branch, broken down by category (Open, OBC-NCL, SC, ST, EWS, PwD), quota (such as HS, OS or AI), and seat pool (Gender-Neutral, Female-only). Every seat allocated during counselling comes from a specific cell of that matrix.

What is the difference between HS, OS, and AI quota?

HS, OS and AI mean Home State, Other State and All India. Match the quota shown in the actual programme matrix. The source note explains where to verify eligibility.

What are Gender-Neutral and Female-only seat pools?

Gender-Neutral seats are open to any candidate. The female-only pool can include supernumerary seats; inspect the exact programme matrix. Eligible female candidates are considered for applicable pools under the official allocation sequence; programme eligibility still applies.

How are reservations applied on top of the seat matrix?

Read the category and PwD columns of the official programme matrix directly. Do not reconstruct the published integer seat counts using a hypothetical percentage split.

Does the seat matrix change during counselling?

Use the latest official publication and any corrections. A historical seat matrix is not a live vacancy count; allocations and vacancies change between rounds.