The city has repurposed some hotels to provide hospital care. It is also converting wedding halls and has several hundred modified railway coaches standing by.
A strict lockdown in place since late March has gradually been lifted, allowing most activities as the economy nose-dived amid the shutdown.
But the number of cases across the vast nation of 1.3 billion people has climbed steeply and is now close to surpassing badly-hit Russia.
Schools, metro trains in cities, cinemas, gyms and swimming pools remain closed and international flights are still grounded.
Authorities have made wearing masks mandatory in public places, while large gatherings are banned and shops and other public establishments are required to implement social distancing.
The western state of Maharashtra, the worst-hit state and home to financial hub Mumbai, recorded over 7 000 new cases while Southern Tamil Nadu state and Delhi recorded more than 4 200 and 2 500 fresh cases respectively.
Mumbai, Delhi and Chennai, Tamil Nadu's capital, are the worst-affected cities.
The national government says it has tackled the virus well but critics allege India is conducting very few tests, leaving the true scale of the pandemic unknown.