Left for 3 weeks now the disc brake is all rusted. What should I do now

Left the city for 3 weeks, and the disc brakes on Nexon is pretty rusted. I haven't driven or even started the cat yet, will use as per need. But when I'll use it..will I face any damages? Will this impact braking? What should I do about it? Or is there nothing to do and I should send it to Tata Service (which I'm not looking forward to) [OC]