Ola has rolled out a new feature called Ola Offline that allows customers to book the Ola cab even when their net connection is not working. When using Ola app if for some reason your net connection fails, you can still book a cab.
The next time you are using the Ola app in absence of a net connection, you will get two options you can either retry or you can book a cab via SMS. When using Book via SMS the default SMS message app will open with some pre-added text by the Ola app.
Just send the SMS and you will soon get another SMS giving details of nearest cabs available across categories. You can then choose the preferred cab category and send, soon you will get the driver / cab details via SMS.
The driver will get your GPS triangulated location but in most cases they will call you for your exact location.