What you show in your image is a connect of Avast to 126.96.36.199. A reverse DNS lookup shows as name sea25.ff.avast.com and a whois lookup shows that this IP is owned by Avast. Thus it is probably perfectly correct for Avast to connect to this server for example for pattern updates or similar. Of course, Avast could also transfer all your secret information from your system to this server but that's the kind of risk you face with any software you install. And, it is very unlikely that a well-known and trusted security company would do it.
As for the seconds IP 188.8.131.52. According to whois it is owned by Level 3 - a very large internet provider which provides connectivity also for various content delivery networks. Thus, it might be such a CDN or it might be not but just looking at the IP address says nothing about the kind of data transferred and if it is dangerous or not.
What is Insecure/Obsolete TCP/UDP Ports/Protocols or the range of ports what is possible to permit attacker attack.
There is no such thing as obsolete ports. There might be some older protocols like gopher (port 70) which are no longer in use but there is no exhaustive list of such ports and the port itself might also be used by different applications.
IPV4 ports range from: 0 --> (2^16)-1. What is the port range of IPV6? Why did someone say that IPV6 is more secure than IPV4? and is possible to narrow the range of TCP/UDP port?
Off-topic. But still: there is no such thing as an IPv4 port or IPv6 port. There are TCP and UDP using ports in the range of up to 2^16-1. They can both use IPv4 or IPv6 as underlying network protocol and this does not affect the range of ports usable.