Switching Older Version and Installing Customized App on Production Image


I have two repositories for customised frappe version (9.2.14) and erpnext version (9.2.13). I am having virtualbox installed and using production image having version for frappe(10.1.16) and erpnext (10.1.18).
erpnext version is getting changed successfully (Checked by bench version command). But when i change the version of frappe. It doesn’t show the version while I run “bench version” command. Shall i assume that it has changed the version successfully?

Also using “bench get-app customizederp bitbucketlink” & same for “bench get-app customizedfrappe bitbucket link”. It gets completely installed in apps folder. But, when I use “bench --site site1.local get-app customizederp” It says, “could not find app”.
Also i renamed customizedfrappe to frappe.
What else needs to be done?

Quick Question :- There can be multiple apps and only one frappe? Am i right? I’m not clear regarding this.

Any suggestions are appreciated, Thankyou.