Final Update !
It was a problem in Garuda settings manager,locales menu. On changing the locale from en us to en in, problems were seen in terminal. localectl, locale-gen, locale -a showed that not all types locales were converted. Some necessary locales like c I guess we're not configured to any locale and left blank. This led to the issue. 2 to 3 users on slackware forum were kind enough to help me instantly. They asked me output of some locale related commands and told me to reinstall fish and glibc.
So the solution that worked was
sudo pacman -Syu glibc fish fish-autopair garuda-fish-config
After installing, in the post install part, I saw it regenerated the locales and configured them flawlessly. After a reboot, now things are fine. All issues are gone. Thanks.