User visits recorded show only a single country (US) always.Even though testing is done from India.
I guess your GeoIP tracking is not active, So Piwik is using browser language for location tracking.
I have added geoip ,it shows installed on admin console. But users location is not being recorded accurately.
Is your webserver behing a proxy or something similar?
Maybe that helps: How do I configure Piwik when the server is installed behind a proxy? - Analytics Platform - Matomo
Then Real IP is not reaching PIWIK because of Proxy. You can use X-Forwarded-For to carry original Client IP through intermediary hops.