[rudra]

i think you should open a new thread asking about that multiple php version and how to manage that. it will be better for everybody.

this is a totally different topic thread.

the basic idea is like this. you install Ondrej ppa and install multiple php versions and extensions from there. next you use .htaccess / filesmatch sethandler / virtualhost include/ location fastcgi_pass (nginx) method to direct which one to use.

you could set one default and specifically select another where you need. that would work too.