I got the solution last , it's a Middleware blocking. As part of security auditing I block host based on IP's . But when put in domain it will block and got 403 Forbidden error. I changed the middleware function below

public function handle($request, Closure $next)
    {
        $allowedHosts = ['127.0.0.1:8000', '10.50.192.128'];

        if (!in_array($request->getHost(), $allowedHosts)) {
            abort(403);
        }

        return $next($request);
    }

as

public function handle($request, Closure $next)
    {
        $allowedHosts = ['careers-ksrtc.karnataka.gov.in'];

        if (!in_array($request->getHost(), $allowedHosts)) {
            abort(403);
        }

        return $next($request);
    }

The problem fixed. Thanks to all especially my collegue Aruna .