After investigation we concluded that this is all due to some error in PTCL DNS servers. PTCL has blocked some Google services in Pakistan and due to this all BlogSpot custom domains in Pakistan are redirecting to google.com.pk and Google is unable to resolve this issue.
PTCL has blocked some of Google's IP addresses in Pakistan. Some of these IP addresses are linked with blogger blogs with custom domains, so in result; all custom domains pointing to blogger blogs are redirecting to google.com.pk in Pakistan.
Internet users are unable to access the blogger blogs with custom domains.
How to solve this Issue ?
Google make some IP address arrangements to solve this issue.
PTCL please check your DNS settings as soon as possible.
Internet Users with PTCL Broadband Connection:
Change your DNS server addresses to 220.127.116.11 and 18.104.22.168 then you will be able to access blogger blogs with custom domains in Pakistan.
You can also acces the blogger blogs by adding the ?m=1 at the end of the link of the blog. For example you can access this post by adding ?m=1 at the end of the link address (Example Link: http://blog.paktron.net/2013/06/blogger-blogs-with-custom-domains-are.html?m=1) look that there is ?m=1 at the end of this link.
Follow the linked guides to change your PTCL DNS to Google's Public DNS.
DSL Installation Guide & How To Speed Up PTCL Internet Connection
Internet Settings for PTCL DSL Modem and Router