At the moment the whole world is fighting the Covid-19 pandemic. It is best to avoid all public transport if you can. It does not make sense to enter places that have large gathering of people. The metro can be very crowded with limited ventilation. Also the surfaces within the stations and trains are prone to being touched by hundreds of people which is a major source of infection.
Keep an eye on the Delhi Metro website here http://www.delhimetrorail.com
If you are visiting Delhi, then my suggestion is that you avoid Delhi metro even when it reopens. If you must, then you should wear face masks that has at least 3 layers. These facemasks not only protect others but prevents air droplets getting through your mouth and nose and infecting you with the coronavirus.
In such a situation, the best is to use a car or a taxi. This will limit the number of people you will come in contact with. When renting a private hire car in Delhi, you must ensure that the vehicle is sanitized before you get into the car.
The best way to confirm this is over the phone with the cab-hire company and with the driver before you step in the car. This ensures that you are minimising the risk of infection.
When you reach your destination, make sure that you use a hand sanitiser to clean your hands if you can’t get hold of soap and water.
When travelling make sure:
That you carry a hand sanitiser
Maintain appropriate social distancing
Cover your mouth and nose
Do not touch surfaces
Do not touch your mouth and nose or try to adjust your mask
So remember there are plenty of car on rent in Delhi for outstation and in-city trips and using them reduces chances of exposure to coronavirus. Be safe.