Network within the ICAI: Reach out to the Coimbatore Branch of the Southern India Regional Council (SIRC) of the ICAI. They often have channels or informal networks where members discuss the sale or merger of practices.
Post in active forums: Rather than relying on an old, inactive thread, create a new "Start Topic" post on the CAclubindia Forum or similar platforms, being specific about the size of the firm, the location, and the type of practice you are looking to acquire.
Professional Listings: Monitor professional journals or newsletters that cater to Chartered Accountants in Tamil Nadu, as practitioners often advertise there when looking to retire or exit their practice.
Direct Outreach: Identify established, mid-sized firms in Coimbatore via the ICAI firm search tool and reach out to senior partners directly to inquire if they are considering succession planning or strategic partnerships.