The problem with a replacement IC is stores like AliExpress and Banggood the shippments from this are banned in India the websites still works but when I go to checkout it just simply says unable to ship to your country. Even if there's any way to import them by third party exporter or something probably it would cost more than the CM4 itself. Finding the IC locally here will be next to impossible. I also have an Older Pi 4B model which has the same issue of blown PMIC.
Seems like the Pi4's and the new model 3B+ are more susceptible to damage because of shorting the power rails. Another older model of 3B just died when I powered it, everything was working fine one day I powered it up and the IC near the USB ports got super hot and now the Pi doesnt boot I dont remember doing any thing wrong with the Pi neither plugging in anything into the USB itself.