Hi Ravi,
If you want to increase the root partition means my suggestion is convert your root partition to LVM then increase the LVM that is better option but u need downtime for this
Why do you think that posting two topics on same subject will get you more valuable information? All possible ways have been covered here and in you other topic
There is another option. If you have a specific application that requires a directory in root, you can always make a new directory and mount the files off of root.