i am relatively new to kubernetes and i am trying to catch things, in my understanding, a pod can have single container as well as multiple containers. Lets say i have a pod with 5 tightly coupled containers and is it possible to autoscale only 2 of them based on the usage. or autoscale will only happen podwise.
No, the definition of a pod is co-located containers. You can vertically scale them differently but there will always be exactly one of each per pod.