The red light on the dashboard is an immobilizer warning light (anti-theft security system). It is a great piece of technology and its purpose is to prevent the vehicle from being stolen. There is nothing to worry about.
Try these suggestions....
Your key fob - also known as a transponder - does not recognise the car key used. Try bringing the key fob closer to the ignition button or on the dashboard
If the car doors or boot is open and the key fob is inside the vehicle - the warning light is telling you have forgotten your key.
The battery in the fob is getting low.