Hi Sanjub22,
You got basically the names of all the places in Kolkata. There is also a Cinebels in the elctronic mall on Central Avenue (Chittaranjan Ave) near Chandni Chowk selling a few Marantz and some speakers (according to Shuvc, another member from Kolkata), but I have never been there.
Digital Acoustics (on Dover Lane) and ProFx (on Hindustan Road) are very close to each other, and you should be able to cover both on a single outing.
SKS is better in 2-channel equipments. I think the only AVRs you would get there are from Cambridge Audio, but they have dealerships of many many speaker brands, Wharfedale, MA, MS, Dali, Dynaudio, Quad, Epos etc etc.
In Profx, the electronics are mostly from Denon, and the speakers are from Focal (expensive) and from Polk and Kef.
Digital Acoustics keeps Tannoys and other speakers (forgot). Do they keep Yamaha? I cannot remember. I was there for a tube amp audition and saw they had a few AVRs, but cannot remember which brands were they. They certainly keep Nad, I remember.
Promises Instruments (opposite Kalamandir, as has been said above) keep mainly Onkyo for electronics and a few speakers (Jamo and ...). They also keep variety of budget cables (like Bandridge and Profigold) useful for low to mid-budget AVR connections.
There is another place (on Landsdowne Road which is now Sarat Bose Ave, closer to Minto Park, I think), I cannot remember the name of, also keeping AVRs and Klipsch speakers. I have never been there.
There is a Nakamichi store on Camac Street near the AJC Road crossing. They keep Boston speakers and some electronics. Been there once for a short time.
There is also a Sonodyne store in the South City Mall. They keep some cables too.
I would generally avoid the e-zones and similar stores where usually you would see a lot of people almost queuing up to get in the viewing and listeining enclosures and very busy and arrogant salesmen with amazing lack of knowledge.
Now, I do not know who keeps Yamaha AVRs in Kolkata. Guys, please help Sanjub22.