Hi @sauraj,

Ubuntu 10.04 has reached it’s end of life about 5 years ago - 01.04.2015. It’s pretty old OS and as such it’s bound to cause issues such as not being able to install newer PHP versions. I’ll highly recommend creating a Droplet with Ubuntu 18.04 and migrating your data there!

Anyway, let’s give it a try and install PHP5.6. FIrst, you’ll need to add the proper repository

sudo apt install software-properties-common
sudo add-apt-repository ppa:ondrej/php
sudo apt update

I can see you’ve tried to add it, however can you try and execute the above 3 commands in the given order again?

Once doe, try again to execute

sudo apt install php5.6

Regards,
KDSys