Chennai's commercial geography is a set of strong neighbourhoods rather than one centre. T Nagar is retail and wholesale, Anna Nagar and Adyar are established residential with clinics and premium services, Velachery and Tambaram serve fast-growing southern suburbs, and the Old Mahabalipuram Road corridor carries the IT workforce. Local search reflects that: a business in Adyar is compared with other Adyar businesses, not with a competitor ten kilometres away.
Language and naming are part of the mechanics. Tamil reviews are common, place names are frequently written in more than one transliteration, and a business may be known by a landmark rather than its street. A profile that states the locality in the form customers use, and replies in the language the review was written in, reads as genuinely local.
Competition in the obvious categories is dense but uneven. Many established Chennai businesses have claimed a profile and then left it: hours unset, no photographs, reviews unanswered for two years. In those categories a fully completed profile with a review-reply routine can outperform a larger competitor, because the visible evidence of attentiveness is what the searcher is looking for.