SIP SHOW PEERS showing Unreachable

I am able to get 200 OK from my SIP client [Written In Java. Based in JAIN SIP].
I am able to register the SIP client Successfully. But when I am checking sip show peers I am getting status=“UNREACHABLE”.
Below is my sip logs after getting 200 OK from Asterisk Server:

OPTIONS sip:David@192.168.0.6:6666;transport=udp SIP/2.0
Via: SIP/2.0/UDP xx.xx.xx.xx:5060;branch=z9hG4bK6f0f9192;rport=5060;received=xx.xx.xx.xx
Max-Forwards: 70
From: "asterisk" <sip:asterisk@xx.xx.xx.xx>;tag=as1df5e302
To: <sip:David@192.168.0.6:6666;transport=udp>
Contact: <sip:asterisk@xx.xx.xx.xx:5060>
Call-ID: 3aa8f5f65b7e550e448e5c043b7713b4@xx.xx.xx.xx:5060
CSeq: 102 OPTIONS
User-Agent: Asterisk PBX 16.7.0
Date: Fri, 17 Jul 2020 07:46:05 GMT
Allow: INVITE,ACK,CANCEL,OPTIONS,BYE,REFER,SUBSCRIBE,NOTIFY,INFO,PUBLISH,MESSAGE
Supported: replaces,timer
Content-Length: 0

Is there is any of Reply I need to send from my code to make my code keep alive at Asterisk Server?
Please suggest.

You need to comply with the SIP RFC, i.e. you need to reply. Any valid reply, including error statutes should work.

Solved the issue…