What do you want to know? The box 12 does support DFS channels but it usually won't get it automatically because as you probably know it can get "pushed away" by radar or defense purposes. So it isn't really a good option to use.

@pioneerkartik V12b supports surely DFS Channels

Operating Frequencies

Device operates within approved frequencies overlapping with the following cellular bands: LTE 255,Unlicensed NII-3 DOWN | LTE 46,TD Unlicensed DOWN |

Frequency Range	Power Output	Rule Parts	Grant Notes	App #
2.412-2.462 GHz	468 mW	15C	CC, MO	1.1
5.18-5.24 GHz	404 mW	15E	CC, MO	2.1
5.18-5.24 GHz	404 mW	15E	CC, MO	3.1
5.26-5.32 GHz	204 mW	15E	CC, MO, ND	3.3
5.5-5.72 GHz	247 mW	15E	CC, MO, ND	3.4
5.745-5.825 GHz	406 mW	15E	CC, MO	2.2
5.745-5.825 GHz	406 mW	15E	CC, MO	3.2

Thanks for the responses.

Actually when I enable 5G to any dfs channels, the 5G radio is turned off. Only when I configure to any non dfs then it gets turned ON . Any inputs here ?

It is possible that your radio is not programmed to use the DFS-channels @pioneerkartik .

Please see your owners-manual for details.

By the way:

5G is an expression for mobile use, just like 3G, 4G and 4G+

The 5.0-wifi AC-band is what we  are talking about.

To be able to use the 5GHz DFS channels the router must wait for at least 60 seconds to ensure the channel is clear. If your channel width is 80Mhz, you are using 4 20Mhz channels, so this takes 4x60seconds

In the EU the channels 120 to 128 are used by weather radar, it is spec'd in DFS that the router must wait 10 minutes when using these channels, so avoid these.

So maybe if you wait longer the 5Ghz radio will appear after finishing the scans.

Edit: You can find documentation about this when searching for “Channel Availability Check” (CAC)