@SukumarCR700 

Suspect you have SMART CONNECT on? If you do, ONLY one SSID is used, the 2.4Ghz one, but the router determines the Frequency you connect to, 2.4 or 5Ghz.

Now you might be on the 5Ghz channel/frequency? That doesn't go as far as the 2.4Ghz band. So when you are too far away from the router it would drop?

Otherwise, it could be Interference.

You probably need to disable SMART CONNECT and then run a Lan Analyzer (Acrylic has a free one, Google it, can't put non-TP-LINk URL's here) and run it. If you are using a channel on either SSID that is congested, look for a channel that has less users and set the router setting for wireless to that channel and save it.

  @IrvSp 

Thanks for your reply,

But I don't see smart connect option for router.

I am sitting next router but still I don't see 5G signal

  @SukumarCR700 

Some other questions, what mode is it running in, Router or Bridged mode?

What IS the device that is having a problem? Make and Model as well as Network Adapter make/model.

Can ANY other device see the 5Ghz signal?

  @IrvSp 

Device is in router mode.

No device is seeing 5G.

I was working till June.

  @SukumarCR700,

Probably need to contact TP-LINK Support for this, but IS the 5Ghz Radio on?

@SukumarCR700,

Your screen capture for the Radio look odd for the 5Ghz:

I'd think it should show ON?

Like this on the Emulator:

Something probably Support could help, but I'd try rebooting the router and see if that helps, and maybe a RESET to shipped state, but you'd have to know what settings you changed possibly to put them back. DO NOT used a SAVE settings that could be bad?