In most markets an exchange enforces conformance and risk limits: your order must be well-formed and within your limits, and beyond that your strategy is your business. In India the exchange is a gatekeeper of the algorithm itself.

Since SEBI circulars of 30 March 2012 and 21 May 2013, algo orders must carry an exchange-issued unique ID, brokers need exchange permission before offering algo trading at all, and orders must route through broker servers with risk controls attached. Colocation fairness — published latency, equitable rack allocation — followed in May 2015.

A retail-specific layer arrived in February 2025: individuals get 10 orders per second per segment without registration, using a static IP mapped to their API key; beyond that, exchange registration and a unique algo ID are mandatory. And “black-box” algorithms — those whose logic is not disclosed — require Research Analyst registration.

That last clause is the one to have ready. A regulator requiring you to register as a research analyst because your strategy logic is hidden is a category of rule that does not exist in US or EU practice, and it changes what you can build as a product.

NSE ran a free front end called NOW and withdrew it effective 28 December 2020, having extended the original September date to accommodate pandemic-era migrations. After that, brokers either built on NSE's member APIs or bought a third-party front end.

• ODIN (63 moons) — cited at roughly 70% of the retail broking software market. Source is a broker-comparison site, so treat the number as indicative.
• NEST (originally Omnesys) — roughly 20%, 200+ broking firms. Acquired by Thomson Reuters in June 2013, then passed to Refinitiv and on to LSEG.
• OmneNEST — and here the loop closes: Omnesys's original founders relaunched in 2023, backed by Zerodha's founders.

On the buy side, Aditya Birla Sun Life AMC's adoption of Bloomberg AIM across its India and Singapore operations is the one clearly documented Indian OMS deployment. Charles River and Aladdin could not be confirmed at any Indian institution for its own book — what exists is BlackRock's own large India operations centre supporting the parent's global clients, which is a very different job from an Indian asset manager running Aladdin.