What's the exact geographical dimension range which can be taken offline in Google Maps? Today, I tried to take my whole country (India) offline, but Google Maps ignored it saying its very large, zoom in. It has also ignored my street saying its too small, zoom out.

I want to know the limits to which Make Map Offline is restricted.

Version of Google Maps: 6.12.0
The limit is actually placed on virtual size of the downloaded area. The upper limit is approximately 80MB of data, and the lower limit is smaller than maps displays, somewhere below 100KB, equivalent to around .6 square miles.

Here is one place that mentions the 80MB limit. In my own testing, I was able to download up to 87MB of data, which is approximately 5625 square miles.

This may have been coincidence, but in my testing, the allowable size ranged from a square .75 miles on a side to a square 75 miles on a side.