Here are some of the top and most prominent real‑estate developers active in Kolkata (mix of long‑standing local groups and national builders with major Kolkata projects). I’ve included a short note about each and a source for verification.

• Ambuja Neotia Group — Kolkata‑headquartered, known for large townships, malls (City Centre), hospitality projects and several landmark residential/commercial developments in the city and New Town. (ambujaneotia.com)

• Merlin Group — Kolkata‑based developer with large mixed‑use projects, malls (Acropolis brand) and a major ongoing investment pipeline in West Bengal. (economictimes.indiatimes.com)

• Godrej Properties — national developer with recently announced large land acquisitions and residential projects in Kolkata (including plotted development in Joka). (realty.economictimes.indiatimes.com)

• South City Projects / consortium (Emami, Merlin, Shrachi, Sureka, JB, others) — developer/consortium behind major projects such as South City Mall and Altair; South City is a major name in Kolkata real estate. (Note: South City Projects was part of a significant transaction referenced in press coverage.) (timesofindia.indiatimes.com)

• Shrachi Realty / Shrachi Group — regional developer with large township and residential projects (Urbana, Renaissance township and other developments across Kolkata & Bengal). (shrachirealty.com)

Other noteworthy developers with substantial Kolkata exposure

• Bengal Ambuja / Ambuja‑related entities — major regional developer involved in mass‑housing, townships and retail (City Centre malls). (ambujaneotia.com)
• DLF (national) — has executed large projects in New Town and owned IT park assets in Kolkata (has transacted some assets recently). (livemint.com)
• Merlin / Emami / RDB / Primarc and other regional groups — several regionally important players and joint‑venture consortia shape Kolkata’s market (mentioned above and in local press). (timesofindia.indiatimes.com)

If you’d like, I can:

• Narrow this to “top” by a specific metric (most sales, largest land bank, highest number of delivered units, or best resale value) and produce a ranked list with supporting data and links; or
• Provide contact/website details and notable projects for any of the developers above.