thanks @uzanto, I just learnt of a new command, iw, very interesting. In fact I found a blog by a linux jet-setter who set up a button on his desktop to automatically configure his wireless locale depending on the country he visits.
Setting my locale to IN (india), I get
# iw reg get
global
country IN: DFS-JP
(2402 - 2482 @ 40), (N/A, 20), (N/A)
(5170 - 5250 @ 80), (N/A, 20), (N/A), AUTO-BW
(5250 - 5330 @ 80), (N/A, 20), (0 ms), DFS, AUTO-BW
(5735 - 5835 @ 80), (N/A, 20), (N/A)
which now lists the 2.4 GHz bands from 2.402 to 2.482 which includes ch 13 but excludes ch 14 at 2.484.
However, in both cases (before and after changing my locale), the 2,4 GHz band reports channel 13 & 14 as disabled,
# iw list
...
Band 1:
...
Frequencies:
* 2412 MHz [1] (16.0 dBm)
* 2417 MHz [2] (16.0 dBm)
* 2422 MHz [3] (16.0 dBm)
* 2427 MHz [4] (16.0 dBm)
* 2432 MHz [5] (16.0 dBm)
* 2437 MHz [6] (16.0 dBm)
* 2442 MHz [7] (16.0 dBm)
* 2447 MHz [8] (16.0 dBm)
* 2452 MHz [9] (16.0 dBm)
* 2457 MHz [10] (16.0 dBm)
* 2462 MHz [11] (16.0 dBm)
* 2467 MHz [12] (16.0 dBm)
* 2472 MHz [13] (disabled)
* 2484 MHz [14] (disabled)
However the fact that these channels are actually listed, would make me think that they are disabled at the kernel level rather than a HW block as suggested by @Dwaff.
Your thoughts?
[EDIT]
Apparently some people are able to enable these channels using iw reg set JP
.