You are working on Two projects , Both involves OAF

one instance is on 11.5.10.2 

one instance is on 12.2.5

can you setup development environment for both these instance are in your PC/LAPTOP.

Jdeveloper 10 g is used for R12

Jdeveloper 9i is used for 11i

so we can have 2 Jdevelopers in Local machine . But when we starting the Jdeveloper we have to change the environment variable named JDEV_USER_HOME . it should point to jdev folder where all our source codes lies.