How many times can you spot the letter "t" in:
Q: Site Url in farm sulotion Can you please let me know if I can change the url site after deployment?
for example I developed a user control within (sp-p/en)
but I want it within the subsite (sp-p/en/dept)
is there a way to change the url requested in the first step of project in farm solution without having to create it all over again?

A: Do you mean that you want to this solution can use in the subsite?
If yes, A feature with "Site collection" scope will work for all your subsites when activated at site collection level.
It will also automatically work for all subsites you create after activation (your exemple with sp-p/en/dept sub site).
This is a reference about Understanding Features and Feature Scope.

user
I counted sixty-four "t"s in that text.
assistant